chore: document release process

Author: johnstcn

README.md

@@ -184,3 +184,41 @@ Pending feedback, we're considering the following features:
 In the short term, AgentAPI solves the problem of how to programmatically control coding agents. As time passes, we hope to see the major agents release proper SDKs. One might wonder whether AgentAPI will still be needed then. We think that depends on whether agent vendors decide to standardize on a common API, or each sticks with a proprietary format.
 
 In the former case, we'll deprecate AgentAPI in favor of the official SDKs. In the latter case, our goal will be to make AgentAPI a universal adapter to control any coding agent, so a developer using AgentAPI can switch between agents without changing their code.
+
+## For Maintainers
+
+### Release Process
+
+Before performing a release, perform a local "smoke-test".
+If everything seems OK, you can proceed to do the following:
+
+1. Update the version string in the following places:
+   - `openapi.json`
+   - `chat/package.json`
+   - `lib/httpapi/server.go`
+2. Add details in `CHANGELOG.md` on what changed.
+3. Create a PR with the subject `chore: update version to X.Y.Z`
+4. Once the above PR is approved and merged, create a new git tag `vX.Y.Z` pointing to the commit of the above PR merged to `main`:S
+
+   ```shell
+     # Fetch existing tags first!
+     git fetch --tags
+     git tag -a vX.Y.Z -m 'vX.Y.Z'
+   ```
+
+5. Push the tag:
+
+   ```shell
+      git push origin tag vX.Y.Z
+   ```
+
+6. Visit `https://github.com/coder/agentapi/releases/tag/vX.Y.Z` and "Create release from tag".
+
+   - Select the tag you pushed previously.
+   - Select the previous tag and "Generate release notes". Amend as required.
+   - **IMPORTANT:** un-check "Set as latest release" and check "Set as a pre-release".
+   - Click "Publish Release". This will trigger a "Build Release Binaries" CI job.
+
+7. Visit `https://github.com/coder/agentapi/actions/workflows/release.yml` and monitor the status of the job that was created in the previous step. This will upload the built assets to the corresponding release.
+
+8. Once the updated assets are released, you can now visit `https://github.com/coder/agentapi/releases/tag/vX.Y.Z`, click "Edit" (✎), and check "Set as latest release".