Establish timeline for year-end donation campaign takeover of about:tor

Each year from ~mid-October through the end of December, the Tor Project runs its year-end fundraising campaign (aka "YEC"). This is the time during which we raise the most money per year from individual donors. A key strategy in this campaign is a branded takeover of about:tor (desktop + mobile) that includes the year-end campaign "mini brand," new assets, a fundraising message, and a donate button.

Based on a conversation with @richard and looking at the release calendar (https://nc.torproject.net/apps/calendar/p/Dy5spytzmYoJPieT/dayGridMonth/2023-10-01), my understanding is that there will be an early October TB release and that this will likely be the best release in which to include about:tor YEC takeover assets.

I'd like to make a plan to get the about:tor year-end campaign takeover assets ready for this early October release. Ideally, the about:tor takeover would not launch with that release, but would be included in the package. The campaign launch assets would be gated until mid-October, with another gated release early/mid-November.

To put it another way:

• first week of October - TB release
• Monday, October 16 - gated YEC takeover of about:tor appears
• Monday, November 13 Wednesday, November 22, roughly - second gated YEC takeover of about:tor appears, based on FF release timing and need to push back match confirmation.

All of that being said, I'd like to understand, based on an early October release:

• When should about:tor assets be ready?
• When should strings be delivered to localization? (Maybe that's a question for @emmapeel?)
• What else should we know, provide, or otherwise be prepared to deliver to the Apps team to make this as painless as possible (😉)?

@richard please let me know if I missed anything important I should include. cc @nicob