Add all Ex commands

[Ranguna]

When I know part of an Ex command, I can use :Telescope commands to find it.

It would be nice to have all the Ex commands on Cheatsheet instead of having to toggle between :Cheatsheet and :Telescope commands.

It's possible to have an overlap between the commands that have been manually added into :Cheatsheet and the ones from :Telescope commands, in those cases maybe showing the command from Cheatsheet would be preferable, because those have human descriptions whilst the ones from :Telescope commands don't.