#15104: add backtick code markup.

Doc/library/__main__.rst

@@ -5,19 +5,19 @@
 .. module:: __main__
    :synopsis: The environment where the top-level script is run.
 
-'__main__' is the name of the scope in which top-level code executes.
-A module's __name__ is set equal to '__main__' when read from
+``'__main__'`` is the name of the scope in which top-level code executes.
+A module's __name__ is set equal to ``'__main__'`` when read from
 standard input, a script, or from an interactive prompt.
 
 A module can discover whether or not it is running in the main scope by
-checking its own __name__, which allows a common idiom for conditionally
-executing code in a module when it is run as a script or with `python
--m` but not when it is imported:
+checking its own ``__name__``, which allows a common idiom for conditionally
+executing code in a module when it is run as a script or with ``python
+-m`` but not when it is imported:
 
    if __name__ == "__main__":
        # execute only if run as a script
        main()
 
 For a package, the same effect can be achieved by including a
-__main__.py module, the contents of which will be executed when the
-module is run with -m.
+``__main__.py`` module, the contents of which will be executed when the
+module is run with ``-m``.