.functions returns also keywords

[friedger]

In addition to .functions, a meta command .keywords would help beginners.

.keywords would display

true
false
block-height
burn-block-height
none
tx-sender

Alternatively, the keywords are displayed different in the result list of .functions

[agraebe]

@lgalabru I don't have access, but this one could be a good first issue

[obycode]

This is still a problem, though the command is now ::list_functions.

[csgui]

Just opened a pull request (#737) to fix this (old :-)) issue. Cheers!