Fix invalid literals in generated rst docs

Before this change, API docs that look like this:

	…adding [param character]s to the right of the string.

would turn into rst files that look like this:

	…adding ``character``s to the right of the string.

That reStructuredText is invalid and causes warnings when the docs repo
is built.

doc/tools/make_rst.py

@@ -1480,6 +1480,8 @@ def format_text_block(
                                 )
 
                         tag_text = f"``{link_target}``"
+                        escape_pre = True
+                        escape_post = True
 
             # Formatting directives.