chore(README): Add a section about the container image and gitea container registry.

README.md

@@ -1,7 +1,7 @@
 # Handmade Revolt
 Fork of Revolt (now Stoat chat) maintained by the handmade cities community.
 
-## Deploying a new release
+## Deploying a new release (TODO: Adjust this for handmadecities)
 
 Ensure `.env.local` points to `https://app.revolt.chat/api`.
 
@@ -22,6 +22,29 @@ ssh $REMOTE
 tmux a -t 4
 ```
 
+## Container image
+
+Releases publish a linux/amd64 image to the Gitea package registry at
+`git.handmadecities.com/HMC/handmade-revolt-web-client` (tags: `<version>`,
+`<major>.<minor>`, and `latest`).
+
+The registry requires authentication even for pulls (anonymous pull is not
+supported by Gitea). On a host that needs to pull the image, log in once with a
+**read-only** token (a token scoped to `read:package`); the credentials are
+saved to `~/.docker/config.json` (or `/root/.docker/config.json`) and persist across reboots:
+
+```bash
+echo '<PACKAGE_PULL_TOKEN>' | docker login git.handmadecities.com -u <pull-username> --password-stdin
+
+docker pull git.handmadecities.com/HMC/handmade-revolt-web-client:latest
+```
+
+Notes:
+
+-   `~/.docker/config.json` is per-user so you'll need to log in separately from all users that will need to pull images.
+-   Credentials are stored base64-encoded, not encrypted; keep the file at `chmod 600` and use a `read:package`-only token so a leak can't push.
+-   Rotate by running `docker login` again, or `docker logout git.handmadecities.com` to remove the stored credential.
+
 # Revite
 
 ## Description