Reference Forums instead of Discord in some more places

What have you done in this MR?

• Removed some more refs to Discord per https://forum.2009scape.org/viewtopic.php?t=315-list-of-places-the-discord-is-listed-so-we-can-replace-it-with-easy-access-to-forums

Are there any tricky things testers should keep an eye out for?

• No

• Yes, as follows:

• I have tested these changes thoroughly.

• This requires extra testing due to changes to architecture or other similarly risky changes.

• I used the Thanos Tool for any JSON edits where possible, and have attached screenshots of any changes.

• I acknowledge that this contribution will be released under the AGPL license.