Add release process issue template

A Github issue template to help formalizing the release process, in
order to avoid human errors in the process.

Closes: https://github.com/damus-io/damus/issues/2752
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>

.github/ISSUE_TEMPLATE/app_release.md

@@ -0,0 +1,52 @@
+---
+name: App release process
+about: Begin preparing for a new app release
+title: 'Release: '
+labels: release-tasks
+assignees: ''
+
+---
+
+A new version release. Please attempt to follow the release process steps below in the order they are shown.
+
+## TestFlight release candidates
+
+### Release candidate 1
+
+**Version:** _[Enter full build information for the release candidate, including major and minor version number, build number, and commit hash]_
+
+1. [ ] Merge in all needed changes to `master`
+2. [ ] Check CI, make sure it is passing
+3. [ ] Prepare preliminary changelog as a draft PR: _[Enter PR link to changelog here]_
+4. [ ] Make a _release_ build and submit to the internal TestFlight group via our new Release candidate workflow in Xcode Cloud.
+5. [ ] Prepare short screencast style video with main changes for the announcement
+6. [ ] Publish release build to these TestFlight groups:
+    - [ ] Alpha testers group
+    - [ ] Translators group
+    - [ ] Purple group
+7. [ ] Publish announcement on Nostr
+
+
+_[Duplicate this release candidate section if there is more than one release candidate]_
+
+
+## App Store release
+
+1. [ ] Release candidate checks:
+    - [ ] Release candidate has been on Purple TestFlight for at least one week
+    - [ ] No blocker issues came from feedback from Purple users (double-check)
+    - [ ] Check with stakeholders
+    - [ ] Check with developers & product for any release showstoppers (e.g., critical newfound bugs)
+2. [ ] Thorough check on release notes
+3. [ ] Submit to App Store review (with manual publishing setting enabled)
+4. [ ] Get App Store approval from Apple
+5. [ ] Prepare announcement
+7. [ ] Publish on the App Store and make announcement
+8. [ ] Publish changelog and tag commit hash corresponding to the release
+9. [ ] Perform a version bump on the repository, in preparation for the next release
+
+
+## Notes/others
+
+_Enter any relevant notes here_
+