Additional website commands

[distributive]

It might be a nice QoL feature to have quick links for:

• https://www.warwicktabletop.co.uk/timetable/
• https://www.warwicktabletop.co.uk/events/
• https://www.warwicktabletop.co.uk/page/codeofconduct/
• https://www.warwicktabletop.co.uk/exec/
• https://www.warwicktabletop.co.uk/votes/ (for during elections)

[the-Bruce]

Bonus points for it automagically pulling a sitemap on startup from the website to generate these commands, instead of hard-coding them into the bot (this would need a PR to the website too, though)