refactor!: rename vim.pretty_print => vim.print

Problem:
The function name `vim.pretty_print`:
1. is verbose, which partially defeats its purpose as sugar
2. does not draw from existing precedent or any sort of convention
   (except external projects like penlight or python?), which reduces
   discoverability, and degrades signaling about best practices.

Solution:
- Rename to `vim.print`.
- Change the behavior so that
  1. strings are printed without quotes
  2. each arg is printed on its own line
  3. tables are indented with 2 instead of 4 spaces
- Example:
  :lua ='a', 'b', 42, {a=3}
  a
  b
  42
  {
    a = 3
  }

Comparison of alternatives:
- `vim.print`:
  - pro: consistent with Lua's `print()`
  - pro: aligns with potential `nvim_print` API function which will
    replace nvim_echo, nvim_notify, etc.
  - con: behaves differently than Lua's `print()`, slightly misleading?
- `vim.echo`:
  - pro: `:echo` has similar "pretty print" behavior.
  - con: inconsistent with Lua idioms.
- `vim.p`:
  - pro: very short, fits with `vim.o`, etc.
  - con: not as discoverable as "echo"
  - con: less opportunity for `local p = vim.p` because of potential shadowing.

runtime/doc/lua-guide.txt

@@ -10,16 +10,16 @@
 ==============================================================================
 Introduction                                                         *lua-guide*
 
-This guide will go through the basics of using Lua in Neovim. It is not meant
+This guide will go through the basics of using Lua in Nvim. It is not meant
 to be a comprehensive encyclopedia of all available features, nor will it
 detail all intricacies. Think of it as a survival kit -- the bare minimum
-needed to know to comfortably get started on using Lua in Neovim.
+needed to know to comfortably get started on using Lua in Nvim.
 
 An important thing to note is that this isn't a guide to the Lua language
-itself. Rather, this is a guide on how to configure and modify Neovim through
+itself. Rather, this is a guide on how to configure and modify Nvim through
 the Lua language and the functions we provide to help with this. Take a look
 at |luaref| and |lua-concepts| if you'd like to learn more about Lua itself.
-Similarly, this guide assumes some familiarity with the basics of Neovim
+Similarly, this guide assumes some familiarity with the basics of Nvim
 (commands, options, mappings, autocommands), which are covered in the
 |user-manual|.
 
@@ -27,7 +27,7 @@ Similarly, this guide assumes some familiarity with the basics of Neovim
 Some words on the API                                            *lua-guide-api*
 
 The purpose of this guide is to introduce the different ways of interacting
-with Neovim through Lua (the "API"). This API consists of three different
+with Nvim through Lua (the "API"). This API consists of three different
 layers:
 
 1. The "Vim API" inherited from Vim: |ex-commands| and |builtin-functions| as
@@ -35,14 +35,14 @@ well as |user-function|s in Vimscript. These are accessed through |vim.cmd()|
 and |vim.fn| respectively, which are discussed under |lua-guide-vimscript|
 below.
 
-2. The "Neovim API" written in C for use in remote plugins and GUIs; see |api|.
+2. The "Nvim API" written in C for use in remote plugins and GUIs; see |api|.
 These functions are accessed through |vim.api|.
 
 3. The "Lua API" written in and specifically for Lua. These are any other
 functions accessible through `vim.*` not mentioned already; see |lua-stdlib|.
 
 This distinction is important, as API functions inherit behavior from their
-original layer: For example, Neovim API functions always need all arguments to
+original layer: For example, Nvim API functions always need all arguments to
 be specified even if Lua itself allows omitting arguments (which are then
 passed as `nil`); and Vim API functions can use 0-based indexing even if Lua
 arrays are 1-indexed by default.
@@ -58,7 +58,7 @@ convenient to use from Lua.
 ==============================================================================
 Using Lua                                                  *lua-guide-using-Lua*
 
-To run Lua code from the Neovim command line, use the |:lua| command:
+To run Lua code from the Nvim command line, use the |:lua| command:
 >vim
     :lua print("Hello!")
 <
@@ -69,10 +69,10 @@ local keyword are not accessible outside of the command. This won't work:
     :lua print(foo)
     " prints "nil" instead of "1"
 <
-You can also use `:lua=`, which is the same as `:lua vim.pretty_print(...)`,
-to conveniently check the value of a variable or a table:
+You can also use `:lua=`, which is equivalent to `:lua vim.print(...)`, to
+conveniently check the value of a variable or a table:
 >vim
-    :lua=package
+    :lua =package
 <
 To run a Lua script in an external file, you can use the |:source| command
 exactly like for a Vimscript file:
@@ -92,7 +92,7 @@ Finally, you can include Lua code in a Vimscript file by putting it inside a
 ------------------------------------------------------------------------------
 Using Lua files on startup                                    *lua-guide-config*
 
-Neovim supports using `init.vim` or `init.lua` as the configuration file, but
+Nvim supports using `init.vim` or `init.lua` as the configuration file, but
 not both at the same time. This should be placed in your |config| directory,
 which is typically `~/.config/nvim` for Linux, BSD, or macOS, and
 `~/AppData/Local/nvim/` for Windows. Note that you can use Lua in `init.vim`
@@ -279,7 +279,7 @@ Note that you cannot directly change fields of array variables. This won't
 work:
 >lua
     vim.g.some_global_variable.key2 = 400
-    vim.pretty_print(vim.g.some_global_variable)
+    vim.print(vim.g.some_global_variable)
     --> { key1 = "value", key2 = 300 }
 <
 Instead, you need to create an intermediate Lua table and change this:
@@ -287,7 +287,7 @@ Instead, you need to create an intermediate Lua table and change this:
     local temp_table = vim.g.some_global_variable
     temp_table.key2 = 400
     vim.g.some_global_variable = temp_table
-    vim.pretty_print(vim.g.some_global_variable)
+    vim.print(vim.g.some_global_variable)
     --> { key1 = "value", key2 = 400 }
 <
 To delete a variable, simply set it to `nil`:
@@ -350,7 +350,7 @@ use |vim.opt:get()|:
     --> {...} (big table)
     print(vim.opt.smarttab:get())
     --> false
-    vim.pretty_print(vim.opt.listchars:get())
+    vim.print(vim.opt.listchars:get())
     --> { space = '_', tab = '>~' }
 <
 ------------------------------------------------------------------------------
@@ -488,7 +488,7 @@ Autocommands                                            *lua-guide-autocommands*
 An |autocommand| is a Vim command or a Lua function that is automatically
 executed whenever one or more |events| are triggered, e.g., when a file is
 read or written, or when a window is created. These are accessible from Lua
-through the Neovim API.
+through the Nvim API.
 
 ------------------------------------------------------------------------------
 Creating autocommands                             *lua-guide-autocommand-create*
@@ -530,7 +530,7 @@ Examples:
     })
 <
 
-Neovim will always call a Lua function with a single table containing information
+Nvim will always call a Lua function with a single table containing information
 about the triggered autocommand. The most useful keys are
 • `match`: a string that matched the `pattern` (see |<amatch>|)
 • `buf`:   the number of the buffer the event was triggered in (see |<abuf>|)
@@ -667,9 +667,8 @@ cover only the basics of this advanced topic.
 ------------------------------------------------------------------------------
 Creating user commands                           *lua-guide-commands-create*
 
-User commands can be created through the Neovim API with
-`vim.api.`|nvim_create_user_command()|. This function takes three mandatory
-arguments:
+User commands can be created through with |nvim_create_user_command()|. This
+function takes three mandatory arguments:
 • a string that is the name of the command (which must start with an uppercase
   letter to distinguish it from builtin commands);
 • a string containing Vim commands or a Lua function that is executed when the