Delete release checklist

No longer needed, the bash script `bin/build-release` covers all of this.

docs/release-checklist.md

@@ -1,16 +0,0 @@
-# Release checklist
-
-Version: `1.b.c`
-
-- [ ] Create release branch `releases/v1.b.c`
-  - [ ] Unignore `node_modules/` by adding `!` in front in `.gitignore`
-  - [ ] Delete `node_modules/`
-  - [ ] Install production dependencies: `npm install --production`
-  - [ ] Add `node_modules/`: `git add node_modules`
-  - [ ] Commit & push action: `git commit -a -m "Publish v1.b.c."`, then `git push`
-- [ ] Test the action with an example package
-- [ ] Create tags
-  - [ ] `v1.b.c` pointing at the last commit in `releases/v1.b.c`
-  - [ ] `latest` pointing at the latest version of the highest major version
-  - [ ] `v1` pointing at the latest `1.x.x` version
-- [ ] Push tags