✍️ Add OTA Docs (#4187)

* add OTA documentation

* maybe will look better

* nits

* one more nit

* use the right image

docs/deploy-ota.md

@@ -0,0 +1,81 @@
+# OTA Deployments
+
+## Overview
+
+![OTA Deployment](./img/ota-flow.png)
+
+## Internal Deployments
+
+Internal OTA deployments should be performed automatically upon all merges into main. In cases where the fingerprint
+diff results in incompatible native changes, a new client build will automatically be ran and deployed to TestFlight 
+(iOS) or delivered in Slack (Android).
+
+## Production Deployments
+
+### Prerequisites
+
+- Remove any internal client from your device and download the client from the App Store/Google Play. This will help for 
+testing as well as retrieving the build number.
+- You should have signed in to EAS locally through npx eas login. You will need to modify the build number in a 
+subsequent step.
+- Identify the build number of the production app you want to deploy an update for. iOS and Android build numbers are 
+divergent, so you will need to find both
+
+  ![app-build-number](./img/app-build-number.png)
+
+- Ensure that the commit the initial client was cut from is properly tagged in git. The tag should be in the format of 1.X.0
+  - Note: If the commit is not properly tagged, then the OTA deployment will simply fail since the GitHub Action will 
+  not be able to find a commit to fingerprint and diff against.
+
+### Preparation
+
+- Create a new branch from the git tag that the initial release was cut from if no OTA deployment has been made yet for this 
+client. Name this branch `1.X.0-ota-1`
+- If a deployment has been made previously for this release, increment the branch name, i.e. `1.x.0-ota-2`
+- If necessary, cherry-pick the commit(s) that you wish to deploy
+- Ensure that the package.json’s version field is set to the appropriate value. As long as used the correct git tag
+to create your branch from, this should be properly set.
+
+### Deployment
+
+- Update the build number through EAS
+    - Note: This isn’t strictly necessary, but having a step that takes you off of GitHub and into the terminal provides 
+    a little “friction” to avoid fat fingering a release. Since there are legitimate reasons to just “click and deploy”
+    for internal builds, I felt it useful to make sure it doesn’t accidentally become a prod deployment.
+    - Set the build number to the appropriate build number found in the prerequisite steps. Again, this should be the 
+    build number for the current production release you want to deploy for.
+    - `npx eas build:version:set -p ios`
+    - `npx eas build:version:set -p android`
+- Run the deployment
+  - Navigate to https://github.com/bluesky-social/social-app/actions/workflows/bundle-deploy-eas-update.yml
+  - Select the “Run Workflow” dropdown
+  
+    ![run-workflow](./img/run-workflow.png)
+  
+  - Select the branch for the deployment you are releasing.
+  
+    ![branch-selection](./img/branch-selection.png)
+  
+  - Double check the branch selection.
+  - Select the production channel
+  - Enter the version for the client you are releasing to, i.e. 1.80.0
+    - Note: If you do enter an incorrect version here, the deployment will either:
+      - Fail because the action cannot find a commit with your misentered version
+      - Succeed - but with no users receiving the update. This is because the version you entered will not properly 
+      correlate to a _build number_ as well, so no clients in the wild will be able to receive the update.
+  
+        ![other-ota-options](./img/other-ota-options.png)
+  
+  - Triple check the branch selection.
+    - You selected the correct branch
+    - You selected the "Production" channel
+    - You entered the correct version in the format of `1.X.0`.
+  - Press “Run Workflow”
+
+In about five minutes, the new deployment should be available for download. To test:
+
+- Remove the internal build of the app from your device
+- Download the app from the App Store/Google Play
+- Launch the app once and wait approximately 15 seconds
+- Relaunch the app
+- Check the Settings page and scroll to the bottom. The commit hash should now be the latest commit on your deployed branch.