weather: add error handling and format code

pywapi is nice enough to handle exceptions itself,
and putting the error in the returned dict, which
we now use.
Also marked some strings as alternatives and
did a bit of cleanup and code formatting.
Only import JSON files, newline escaping

The bot was importing every file in the alternatives directory.
Changed to import only .json files.

We were using a very esoteric function for newline escaping.
Now using str.replace and escaping tabs as well.
DnD Dice Module fix