[docs] Need readline command and keybinding information (issue 8491)

[vadmium+py at gmail.com]

https://bugs.python.org/review/8491/diff/17570/Doc/library/readline.rst
File Doc/library/readline.rst (right):

https://bugs.python.org/review/8491/diff/17570/Doc/library/readline.rst#newcode31
Doc/library/readline.rst:31: .inputrc in your home directory; see 'GNU
readline
I think “.inputrc” needs quotes or something around it, considering it
starts with a full stop

https://bugs.python.org/review/8491/diff/17570/Doc/library/readline.rst#newcode32
Doc/library/readline.rst:32:
<http://www.gnu.org/software/bash/manual/html_node/Readline-Init-File.html>`
I wonder if it would be better to link to just the Readline
documentation
(https://cnswww.cns.cwru.edu/php/chet/readline/rluserman.html#SEC9),
instead of the Bash documentation. Gnu Readline and Bash seem to be very
closely linked, but refering to the Bash documentation could be
confusing.

https://bugs.python.org/review/8491/