[doc] Fix erroneous backslashes in signatures and names (GH-23658)
The issue being resolved is shown in the 3.10 docs (if you select docs for older versions you won't see a visual glitch).
The newer sphinx version that produces the 3.10 docs doesn't treat the backslash to escape things in some situations it previously did.
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index aecbec5..048cb2a 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -964,7 +964,7 @@
.. versionadded:: 3.7
-.. class:: StringIO(initial_value='', newline='\\n')
+.. class:: StringIO(initial_value='', newline='\n')
A text stream using an in-memory text buffer. It inherits
:class:`TextIOBase`.