diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index d4c1b9a..0a86ac3 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -19,9 +19,11 @@ jobs:
         run: |
           rm -rf docs
           mv bundles docs
-          git checkout -- docs/_config.yml
+          ls -la docs
+          sudo git checkout -- docs/_config.yml
+          ls -la docs
           docker run --rm -v .:/src -w /src qrapps:ci release.py
-          tree /f docs
+          ls -la docs
       - name: release
         run: |
           git config --global user.email "woldemar@mimas.ru"
diff --git a/Dockerfile b/Dockerfile
index 5405f59..4a27b26 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,18 +8,12 @@
 #
 # Check code quality:
 # docker run --rm -it -v .:/src -w /src --entrypoint=prospector qrapps:ci
-#
-# Convert everything to QR codes:
-# docker run --rm -it -v .:/src -w /src qrapps:ci qrs.py --htmldirs=apps --builddir=bundles
 # 
 # Convert single app to QR code:
 # docker run --rm -it -v .:/src -w /src qrapps:ci qr.py --htmldir=apps/demo-clock --builddir=bundles
 #
-# Then run commands from within the build environment, for example
-# docker run --rm -it -u $(id -u):$(id -g) -v $(pwd):/usr/src -w /usr/src curl/curl autoreconf -fi
-# docker run --rm -it -u $(id -u):$(id -g) -v $(pwd):/usr/src -w /usr/src curl/curl ./configure --without-ssl --without-libpsl
-# docker run --rm -it -u $(id -u):$(id -g) -v $(pwd):/usr/src -w /usr/src curl/curl make
-# docker run --rm -it -u $(id -u):$(id -g) -v $(pwd):/usr/src -w /usr/src curl/curl ./scripts/maketgz 8.7.1
+# Convert everything to QR codes:
+# docker run --rm -it -v .:/src -w /src qrapps:ci qrs.py --htmldirs=apps --builddir=bundles
 
 from debian:12
 
diff --git a/README.md b/README.md
index ed91a8b..90aff0c 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,16 @@ All apps follow same rules:
 These codes can be scanned by your device of choice and content pasted directly into browser URL.
 Since QR code content is [Data URL](https://en.wikipedia.org/wiki/Data_URI_scheme), it contains everything needed within itself.
 
+## How to contribute?
+- Create directory in `apps` with appropriate name, then add to it:
+    - `index.html` - main app layout file
+    - `index.js` - app source code
+    - `minify.json` and `uglify.json` - compression configs
+    - `README.md` - app description
+
+    (see `demo-*` apps for file content examples)
+- Use build instructions from [Dockerfile](Dockerfile)
+
 ## Why would you do that?
 For fun, challenge and as a demonstration of modern browser capabilities.
 Fitting entire app in one QR code also keeps them relatively small and simple... until author tries to squeeze code too hard and it becomes unreadeable 😂