remove markdown before checking if a message is a haiku

[twentylemon]

Title. We currently remove a hardcoded list of symbols from the message, but we should also clean up markdown as well.

Discord.py's remove_markdown might be useful.

• https://github.com/duck-dynasty/duckbot/blob/main/duckbot/cogs/messages/haiku.py#L35

[jameshughes89]

Mildly-ish related to #525

[twentylemon]

Yes and no. Though we remove punctuation when checking if a message is a haiku, we keep that punctuation when producing the resultant message. So like three, two seven, two three (words being the number of syllables they are would give:

three, two
seven,
two three

We essentially remove the punctuation so we can lookup how many syllables a word is. So a message like three **two** _seven two_ three should yield:

three two
seven
two three