which-key (was: Adding a "quick-help" menu)

[Stefan Monnier]

>> Yes, but just like there is a difference between auto-completion and
>> tab-completion, there is a difference to be considered here.
> for me the main difference to all other help facilities is,
> that there is zero cognitive burden: It only pops up when I
> hit a prefix key and then don't know what to do.

BTW, AFAICT there are fundamentally two differences between the `C-h`
trick and `which-key-mode`:

A) `C-h` needs an explicit user action, rather than just waiting
   a shot time.  Both options have their advantages.
B) `C-h` displays the result in a less sophisticated way than
   `which-key`.

Regarding (A), in order to avoid the potential occasional annoyance of
the which-key popup, which also solving the discoverability problem of
`C-h`, I guess we should simply change the "echo keystrokes"
functionality so instead of just displaying "C-x-" it could display
something like "C-x-  [Hit C-h for help]".

And regarding (B), it seems to be a small matter of merging the two
codebases so that `C-h` and `which-key` get the same display.


        Stefan