Add RC release candidate post

Closes #1 (closed)

Release candidate update post, covering instructions for pod admins, contributors, and localizers.

content/funkwhale-120-rc-release.md

+Title: Funkwhale 1.2.0 release candidate
+Date: 2021-12-07
+Author: Sporiff
+Category: Announcement
+Slug: funkwhale-120-rc-release
+Summary: On your marks, get set, go! It's time to start testing the Funkwhale 1.2.0 release candidate!
+
+![And now… it's showtime!](https://media2.giphy.com/media/13ZVRnWnmSMaRy/giphy.gif?cid=ecf05e47rzwiu7wk7bjhk0mujxlowxqplnyw8qlq6ozgw192&rid=giphy.gif&ct=g)
+
+Hello again everyone! We come to you in this coldest of months to bring good news! After months of development, the release candidate for Funkwhale 1.2.0 is finally ready to test!
+
+## [Oh boy! What's that?](whats-that)
+
+A release candidate is a snapshot of all of the features and bugfixes we want to ship in the latest release. It's a releasable version of the new update that we can use to give people time to test out the new changes, submit translations, and generally play around with the software to make sure we address any issues before going live with the new version 🕹
+
+## [So, what do I need to do?](what-do-i-need-to-do)
+
+There are a few things you can do to help us get this release into shape!
+
+* If you're a pod administrator, you can install this release candidate somewhere and play around with it to make sure we've tightened all the screws. If you find something that doesn't work how you expect, let us know so we can get on that 🔧
+* If you're a localizer, head on over to [our weblate instance](https://translate.funkwhale.audio) to start updating translations in your language 🌐
+
+Any time you can spare to help us make this release as good as it can be is greatly appreciated 🙏
+
+## [What else do I need to know?](need-to-know)
+
+As always, 1.2.0 brings with it a host of new features, bug fixes, and new designs. We'll cover these in the actual announcement post, but for now there are a few things pod admins and contributors should be aware of regarding the upcoming release:
+
+1. We have removed the outdated JSON web token (JWT) based authorization flow. This means that apps using this flow to authenticate will not be able to talk to pods running 1.2.0 and above. This includes [Otter](https://github.com/apognu/otter). If you're currently using Otter, consider using the official [Funkwhale for Android](https://f-droid.org/en/packages/audio.funkwhale.ffa/) app instead 🎧
+2. We now ship multiarch Docker containers for deployment on ARM devices. This gives you a lot more options for which machines you can run Funkwhale on ⚡️
+3. As announced in a [recent blog post]({filename}./../2021-11-05-aio-deprecation.md), we will be deprecating our all-in-one-Docker container. You don't need to worry about this just yet, but keep it in mind for the future 🔮
+4.  We will be switching our deployment branch from `master` to `main` to keep our terms inclusive. If your Ansible or Docker setup points to `master`, make sure you update those references as soon as possible!