[Doc] Revise docs based on review suggestions

Co-authored-by: Bryan Weber <bryan.w.weber@gmail.com>

doc/doxygen/mainpage.md

@@ -1,6 +1,6 @@
 # %Cantera C++ Reference
 
-Use sidebar to view detailed documentation of the C++ code, or use the following
+Use the sidebar to view detailed documentation of the C++ code, or use the following
 shortcuts:
 
 * Overview of [**Cantera C++ Modules**](modules.html)
@@ -16,8 +16,8 @@ A topical overview is provided as follows:
 * @ref onedGroup (flames, flow domains, boundaries, ...)
 * @ref physConstants (universal constants, built into %Cantera for convenience)
 
-For fundamental scientific theory used for the implementation of %Cantera, refer to the
-[Cantera Science Section](../reference/index.html#science-reference)
-of the [Cantera Website](https://cantera.org).
+Details on the fundamental scientific theories used in the implementation of %Cantera
+are located in the
+[Science Reference Section](../reference/index.html#science-reference).
 
 The %Cantera source code is hosted on [GitHub](https://github.com/Cantera/cantera).

doc/sphinx/develop/doc-formatting.md

@@ -1,8 +1,8 @@
 # Formatting Documentation
 
 Most of Cantera's HTML documentation, with the exception of the C++ API documentation,
-is generated by Sphinx. The C++ API documentation is generated using Doxygen. The
-content used to generate these pages comes from several sources:
+is generated by [Sphinx](https://sphinx-doc.org). The C++ API documentation is generated
+using Doxygen. The content used to generate these pages comes from several sources:
 
 - [reStructuredText](https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html)
   documents (with the `.rst` extension), organized under the `doc/sphinx` subdirectory
@@ -51,7 +51,7 @@ This page provides some notes on useful syntax for writing in these various form
 ## Useful reST syntax
 - Linking to a Sphinx page:
   - `` :doc:`/absolute/path` `` (automatic name)
-- Caution on usage of single backticks versus double backticks -- the former are only for linking to things using the default role (i.e. Python objects)
+- Caution on usage of single backticks versus double backticks -- the former are only for linking to things using the default role (that is, Python objects)
 
 ## Useful Doxygen syntax
 - Linking to a Sphinx page: `[link text](../reference/science/phasethermo/lattice.html)`

doc/sphinx/install/pip.md

@@ -8,7 +8,7 @@ to install the Cantera Python module from [PyPI](https://pypi.org/project/Canter
 There are a few important limitations to note when Cantera is installed from PyPI:
 
 - These packages are compiled without native HDF5 support. The new options for saving
-  and restoring `SolutionArray` and flame objects to/from HDF5 files is not available.
+  and restoring `SolutionArray` and flame objects to/from HDF5 files are not available.
 - These packages are compiled using single-threaded implementations of LAPACK functions,
   and cannot make use of multiple cores to speed up reactor network or flame
   simulations.

doc/sphinx/install/ubuntu.md

@@ -2,8 +2,11 @@
 # Ubuntu Packages
 
 As of Cantera 3.0.0, packages are available for Ubuntu 20.04 (Focal Fossa), Ubuntu 22.04
-(Jammy Jellyfish), Ubuntu 23.04 (Lunar Lobster), and Ubuntu 23.10 (Mantic Minotaur). To
-see which Ubuntu releases and Cantera versions are currently supported, visit the
+(Jammy Jellyfish), Ubuntu 23.04 (Lunar Lobster), and Ubuntu 23.10 (Mantic Minotaur).
+Generally, packages are available for the two most-recent LTS releases as well as the
+non-LTS releases supported on [Launchpad](https://launchpad.net/ubuntu) at the time of
+the Cantera release. To see which Ubuntu releases and Cantera versions are currently
+supported, visit the
 [Cantera PPA](https://launchpad.net/~cantera-team/+archive/ubuntu/cantera).
 
 The available packages are:

doc/sphinx/reference/glossary.md

@@ -41,7 +41,7 @@ PDSS
 
 {.glossary}
 RT
-: Product of the gas constant (R) and the temperature
+: Product of the universal gas constant (R) and the temperature
 
 {.glossary}
 SHE

doc/sphinx/reference/thermo/index.md

@@ -21,7 +21,7 @@ sections describe the species and phase thermodynamic models available in Canter
 : The theory behind some of Cantera's phase models, such as the ideal gas law.
 
 The user must specify the thermodynamic models and provide input data to be used for
-both levels, and these selections must be compatible with one another. For instance: one
+both levels, and these selections must be compatible with one another. For instance, one
 cannot pair certain non-ideal species thermodynamic models with an ideal phase model.
 
 ```{toctree}

doc/sphinx/userguide/compiling-cxx.md

@@ -19,10 +19,10 @@ build systems, namely CMake and SCons.
 
 ### CMake
 
-CMake is a multi-platform build system that uses a high-level project description to
-generate platform-specific build scripts (for example, on Linux, CMake will generate
-Makefiles, and on Windows, it can generate Visual Studio `.sln` files). The
-configuration file for a CMake project is called `CMakeLists.txt`. A typical
+[CMake](https://cmake.org/) is a multi-platform build system that uses a high-level
+project description to generate platform-specific build scripts (for example, on Linux,
+CMake will generate Makefiles, and on Windows, it can generate Visual Studio `.sln`
+files). The configuration file for a CMake project is called `CMakeLists.txt`. A typical
 `CMakeLists.txt` file for compiling a program that uses Cantera might look like this:
 
 ```cmake
@@ -72,10 +72,11 @@ This will create an executable named `sample.exe` in the `build\Release` directo
 
 ### SCons
 
-SCons is a multi-platform, Python-based build system. It is the build system used to
-compile Cantera. The description of how to build a project is contained in a file named
-`SConstruct`. The `SConstruct` file is actually a Python script, which makes it very
-straightforward to add functionality to a SCons-based build system.
+[SCons](https://scons.org/) is a multi-platform, Python-based build system. It is the
+build system used to compile Cantera. The description of how to build a project is
+contained in a file named `SConstruct`. The `SConstruct` file is actually a Python
+script, which makes it very straightforward to add functionality to a SCons-based build
+system.
 
 A typical `SConstruct` file for compiling a program that uses Cantera might look like
 this: