Add an RFC about renaming the default branch of most repos in the org (#225)

Author: gsnedders

rfcs/main_branch_side_repos.md

@@ -0,0 +1,73 @@
+# RFC #XX: Rename `master` branch to `main` in non-test repositories
+
+## Summary
+
+Rename `master` branch to `main` in 
+[web-platform-tests/data-migration](https://github.com/web-platform-tests/data-migration),
+[web-platform-tests/wpt.live](https://github.com/web-platform-tests/wpt.live),
+[web-platform-tests/rfcs](https://github.com/web-platform-tests/rfcs),
+[web-platform-tests/editor](https://github.com/web-platform-tests/editor),
+[web-platform-tests/code-of-conduct-moderations](https://github.com/web-platform-tests/code-of-conduct-moderations), and
+[web-platform-tests/wpt-notes](https://github.com/web-platform-tests/wpt-notes).
+
+
+## Details
+
+Find non-archived repositories whose default branch is not main with:
+
+```sh
+gh api /orgs/web-platform-tests/repos | jq -r '.[] | select(.default_branch != "main" and (.archived | not)) | .html_url + ": " + .default_branch'
+```
+
+Yields:
+
+```
+https://github.com/web-platform-tests/wpt: master
+https://github.com/web-platform-tests/data-migration: master
+https://github.com/web-platform-tests/wpt.live: master
+https://github.com/web-platform-tests/rfcs: master
+https://github.com/web-platform-tests/wpt-metadata: master
+https://github.com/web-platform-tests/editor: master
+https://github.com/web-platform-tests/code-of-conduct-moderations: master
+https://github.com/web-platform-tests/wpt-notes: master
+```
+
+This RFC proposes to rename the default branches of everything *except* `wpt` and `wpt-metadata` to `main`.
+
+Specifically:
+
+### `data-migration`
+
+There are no references to the `master` branch of this repo.
+No further work is expected.
+
+### `wpt.live`
+
+This contains [a few references](https://github.com/search?q=repo%3Aweb-platform-tests%2Fwpt.live+master&type=code) to `master`.
+Two of these appear to refer to the repo itself.
+Both can be fixed to be generic.
+
+### `rfcs`
+
+There are no code references to the `master` branch of this repo.
+No further work is expected.
+
+### `editor`
+
+There are no code references to the `master` branch of this repo.
+No further work is expected.
+
+### `code-of-conduct-moderations`
+
+This contains no references to any `master` branch.
+No further work is expected.
+
+### `wpt-nodes`
+
+There are no code references to the `master` branch of this repo.
+No further work is expected.
+
+
+## Risk
+
+Calamity