Replace the logo and icon with QuestShock artwork; add a GitHub release workflow

README.md

@@ -46,7 +46,11 @@ sideloaded Android app, and needs your own copy of the game data.
   (see [CONFIG.md](CONFIG.md)); `res/controller_profiles/` - the per-controller
   illustrations and labels shown in the Controller Options tab (see
   [CONFIG.md](CONFIG.md)). Both are copied into the APK, as is
-  `res/splash.png`, the startup splash image.
+  `res/splash.png`, the startup splash image. `res/logo.png` is the 1024x1024
+  logo, the master of the launcher icon
+  (`android/app/src/main/res/mipmap-*/ic_launcher.png` are scaled copies of it)
+  and the image to use for store listings; `res/logo_small.png` is the copy
+  shown at the top of this file.
 - `Makefile` - targets:
   - `all` (default) - alias for `dist`.
   - `build-image` - builds the Docker build-image (`./build-image.sh`).
@@ -211,6 +215,25 @@ package on every push, using the build-image as its container (so no
 extra setup is needed in CI beyond the image itself), and publishes the
 resulting tarball to dl.ladkau.de.
 
+### 4.3. GitHub releases
+
+The repository is developed on Gitea, and the GitHub repository is a mirror of
+it. `.github/workflows/release.yml` is GitHub's own workflow (the Gitea build
+is `.gitea/workflows/build.yml`):
+
+- Pushing a tag `vX.Y.Z` builds the Linux and Windows packages and the Quest
+  APK inside the build-image and attaches them to a GitHub release with the
+  same name. A manual run ("Run workflow") builds the same files without
+  releasing them and keeps them as a downloadable workflow artifact.
+- The build-image is pushed to GitHub's container registry (`ghcr.io`) when it
+  does not exist there yet. Its tag is a hash of `build-image/Dockerfile`,
+  `docker-entrypoint.sh` and `build-engine.sh`, so a change to any of them
+  builds a new image (`build-image/VERSION` is not used). The first run is slow
+  because it builds the image.
+- The APK is built with `assembleDebug`, so it is signed with the debug key of
+  the machine that built it. Android only updates an installed app from an APK
+  with the same signing key.
+
 ## 5. Android / Quest build
 
 **Prerequisites:**