docs: release guide (#3821)

Closes #3521

---------

Co-authored-by: Callum Waters <[email protected]>

docs/maintainers/release-guide.md

@@ -0,0 +1,38 @@
+# Release Guide
+
+The target audience for this guide is maintainers of this repo. In general, the release process is as follows:
+
+1. Create a release candidate
+1. Test the release candidate
+    1. If the release candidate is not satisfactory, go back to step 1
+    1. If the release candidate is satisfactory, create an official release
+
+## Release Candidate
+
+### Creating a release candidate
+
+1. Navigate to <https://github.com/celestiaorg/celestia-app/releases/new>.
+1. Choose a version tag based on [Semantic Versioning](https://semver.org/). Include the `-rc` suffix followed by the next integer. RCs start at 0.
+1. Change the target branch to `v1.x` or `v2.x` based on the version you're releasing.
+1. Click **Generate release notes**.
+1. Toggle on the **Set as a pre-relase** checkbox.
+1. **Publish release**.
+
+### After creating the release candidate
+
+1. Wait until CI passes on the release and verify that prebuilt binaries were attached to the release.
+1. Create a PR to bump the celestia-app dependency in [celestia-node](https://github.com/celestiaorg/celestia-node).
+1. [Optional] Start a testnet via auto-devops that uses the release candidate. Confirm it works.
+1. [Optional] Use the release candidate to sync from genesis. Confirm it works.
+
+## Official Release
+
+Follow the [creating a release candidate](#creating-a-release-candidate) section with the following considerations: 
+
+- The version tag should not include the `-rc` suffix.
+- The release notes should contain an **Upgrade Notice** section with notable changes for node operators or library consumers.
+
+After creating the release:
+
+1. Wait until CI passes on the release and verify that prebuilt binaries were attached to the release.
+1. Create a PR to bump the celestia-app dependency in [celestia-node](https://github.com/celestiaorg/celestia-node).