docs(lsp): describe semantic tokens highlight groups with more details

Problem: Description of highlight groups for LSP semantic tokens can be
  more up to date and useful.
  Right now it misses several actually defined highlight groups and
  presents information about Vim highlight groups they are linked to.
  This is both outdated (they link to tree-sitter `@` groups now) and
  redundant (users can see this information with `:Inspect` over the
  group name itself).

Solution: Synchronize the list of groups with specification and provide
  actionable descriptions.

runtime/doc/lsp.txt

@@ -454,30 +454,44 @@ You probably want these inside a |ColorScheme| autocommand.
 Use |LspTokenUpdate| and |vim.lsp.semantic_tokens.highlight_token()| for more
 complex highlighting.
 
-The following groups are linked by default to standard |group-name|s:
+The following is a list of standard captures used in queries for Nvim,
+highlighted according to the current colorscheme (use |:Inspect| on one to see
+the exact definition):
 
-@lsp.type.class          Structure
+@lsp.type.class          Identifiers that declare or reference a class type
-@lsp.type.decorator      Function
+@lsp.type.comment        Tokens that represent a comment
-@lsp.type.enum           Structure
+@lsp.type.decorator      Identifiers that declare or reference decorators and annotations
-@lsp.type.enumMember     Constant
+@lsp.type.enum           Identifiers that declare or reference an enumeration type
-@lsp.type.event          Type
+@lsp.type.enumMember     Identifiers that declare or reference an enumeration property, constant, or member
-@lsp.type.function       Function
+@lsp.type.event          Identifiers that declare an event property
-@lsp.type.interface      Structure
+@lsp.type.function       Identifiers that declare a function
-@lsp.type.keyword        Keyword
+@lsp.type.interface      Identifiers that declare or reference an interface type
-@lsp.type.macro          Macro
+@lsp.type.keyword        Tokens that represent a language keyword
-@lsp.type.method         Function
+@lsp.type.macro          Identifiers that declare a macro
-@lsp.type.modifier       Type
+@lsp.type.method         Identifiers that declare a member function or method
-@lsp.type.namespace      Structure
+@lsp.type.modifier       Tokens that represent a modifier
-@lsp.type.number         Number
+@lsp.type.namespace      Identifiers that declare or reference a namespace, module, or package
-@lsp.type.operator       Operator
+@lsp.type.number         Tokens that represent a number literal
-@lsp.type.parameter      Identifier
+@lsp.type.operator       Tokens that represent an operator
-@lsp.type.property       Identifier
+@lsp.type.parameter      Identifiers that declare or reference a function or method parameters
-@lsp.type.regexp         SpecialChar
+@lsp.type.property       Identifiers that declare or reference a member property, member field, or member variable
-@lsp.type.string         String
+@lsp.type.regexp         Tokens that represent a regular expression literal
-@lsp.type.struct         Structure
+@lsp.type.string         Tokens that represent a string literal
-@lsp.type.type           Type
+@lsp.type.struct         Identifiers that declare or reference a struct type
-@lsp.type.typeParameter  TypeDef
+@lsp.type.type           Identifiers that declare or reference a type that is not covered above
-@lsp.type.variable       Identifier
+@lsp.type.typeParameter  Identifiers that declare or reference a type parameter
+@lsp.type.variable       Identifiers that declare or reference a local or global variable
+
+@lsp.mod.abstract        Types and member functions that are abstract
+@lsp.mod.async           Functions that are marked async
+@lsp.mod.declaration     Declarations of symbols
+@lsp.mod.defaultLibrary  Symbols that are part of the standard library
+@lsp.mod.definition      Definitions of symbols, for example, in header files
+@lsp.mod.deprecated      Symbols that should no longer be used
+@lsp.mod.documentation   Occurrences of symbols in documentation
+@lsp.mod.modification    Variable references where the variable is assigned to
+@lsp.mod.readonly        Readonly variables and member fields (constants)
+@lsp.mod.static          Class members (static members)
 
 ==============================================================================
 EVENTS                                                            *lsp-events*