Slack Export: Output file name includes whitespace characters #44
Description
Problem
Just trying uvx rapporto slack export "https://acme.slack.com/archives/D018V8WDABA/p1738873838427919", it produced an output file like slack_export/teamcrazybanana_qabot\ 2025W14_25-03-31-12_20.md, while the channel name is called #team-crazy-banana and the title of the first post in the referenced conversation is qa-bot 2025W14.
Observations
The processing removes dashes, but keeps whitespace. Also, the year does not use four digits, and the separation between date and time is wrong.
Solution
It would be sweet if this would not include whitespace or other special characters. Instead of sanitizing strings by hand, let's use a generic slugify method for a better DWIM.
/cc @WalBeh