Update Mozilla links everywhere to the Hubs-Foundation versions, or to placeholders until suitable documents can be recreated.  Placeholders are marked with (TBD) where possible.
Update various documentation files to include missing repositories, remove outdated information, and be more in line with the current state of things.  More work on this is needed.
References to Mozilla's name are either removed or changed to refer to Hubs, its community, or the Hubs Foundation.

Note: links in .env files and habitat files are unchanged to ensure nothing breaks.  The same for references to mozillareality.

Rewrite the PROMOTION.md file to be generic and applicable to all Hubs instances.
Removes the right for the owner of the instance to use the promoted avatar in advertising without explicit consent.

Replace the discord-bot-logo.png with a generic version.
Replace the hmc-logo.png with a generic version.
Remove the home-hero-background.jpg as it is unused.
Replace the spoke_logo_black.png with a generic version.
Remove discord.mp4 and discord.webm because they have too much branding to easily replace.
It would be nice to have replacements for the Discord videos eventually, for now they have been switched out on the Discord bot page with additional copies of the logo images.
Replace the HmcLogo.svg with a generic version.

Update the Invite Bot to Server link to point to the Hubs Discord Bot GitHub repository instead of the Mozilla Hubs team's Google form which contained outdated links, offers of support, and requests for information to be shared with the Mozilla Hubs team.

[Mozilla Branding Removal] tex's first try on contributing to an open source project