follow-up #17692: more inline syntax highlighting (#17837)

doc/rstcommon.rst

@@ -1,6 +1,51 @@
+..
+  Usage of this file:
+     Add this in the beginning of *.rst file::
+
+       .. default-role:: code
+       .. include:: rstcommon.rst
+
+     It's the current trick for brevity and compatibility with both Github and
+     rst2html.py, considering that Github cannot highlight Nim in
+     RST files anyway and it does not include files.
+     This way interpreted text is displayed with monospaced font in Github
+     and it's displayed an Nim code in both rst2html.py
+     (note ".. default-role:: Nim" above) and `nim rst2html`.
+
+     For files that are user manual and consist of stuff like cmdline
+     option description, use 'code' as a **real** default role:
+
+     .. include:: rstcommon.rst
+     .. default-role:: code
+
+.. define language roles explicitly (for compatibility with rst2html.py):
 
 .. role:: nim(code)
    :language: nim
 
 .. default-role:: nim
 
+.. role:: c(code)
+   :language: c
+
+.. role:: cpp(code)
+   :language: cpp
+
+.. role:: yaml(code)
+   :language: yaml
+
+.. role:: python(code)
+   :language: python
+
+.. role:: java(code)
+   :language: java
+
+.. role:: csharp(code)
+   :language: csharp
+
+.. role:: cmd(code)
+
+.. role:: program(code)
+
+.. role:: option(code)
+