docs(docker): move Dockerfile usage comments to README

- Dockerfile header reduced to single line reference to README
- Added comprehensive 'Docker Usage' section to README.md
- Easier to maintain documentation in one place
- Includes all usage examples: build, test, runtime, docker-compose

Dockerfile

@@ -1,27 +1,5 @@
 # Rentgen Browser Extension - Docker Build
-#
-# Usage:
-#   Build and extract artifacts directly:
-#     docker buildx build . --output artifacts
-#
-#   Build with tests (typecheck + lint):
-#     docker build --build-arg RUN_TESTS=true -t rentgen .
-#
-#   Or traditional build (creates full development environment):
-#     docker build -t rentgen .
-#     docker run --rm rentgen ls -lh /app/web-ext-artifacts/
-#
-#   Run commands in the container:
-#     docker run --rm rentgen npm run build:chrome
-#     docker run --rm rentgen npm run typecheck
-#
-#   Run extension in Firefox (headless):
-#     docker build --target runtime -t rentgen-run .
-#     docker run --rm -it rentgen-run
-#
-#   Using docker-compose:
-#     docker-compose up rentgen_check     # Build only
-#     docker-compose up rentgen_run       # Run in Firefox
+# See README.md for detailed usage instructions
 
 # Build stage
 FROM node:lts AS builder

README.md

@@ -41,6 +41,50 @@ Firefox: https://addons.mozilla.org/en-US/firefox/addon/rentgen/
 3. Click _Load Temporary Add-on..._ button
 4. Pick the zip archive from last step of build process.
 
+## Docker Usage
+
+### Build and extract artifacts directly
+
+```bash
+docker buildx build . --output artifacts
+```
+
+This will build the extension and extract the `.zip` file to the `artifacts/` directory.
+
+### Build with tests (typecheck + lint)
+
+```bash
+docker build --build-arg RUN_TESTS=true -t rentgen .
+```
+
+### Traditional build (creates full development environment)
+
+```bash
+docker build -t rentgen .
+docker run --rm rentgen ls -lh /app/web-ext-artifacts/
+```
+
+### Run commands in the container
+
+```bash
+docker run --rm rentgen npm run build:chrome
+docker run --rm rentgen npm run typecheck
+```
+
+### Run extension in Firefox (headless)
+
+```bash
+docker build --target runtime -t rentgen-run .
+docker run --rm -it rentgen-run
+```
+
+### Using docker-compose
+
+```bash
+docker-compose up rentgen_check     # Build only
+docker-compose up rentgen_run       # Run in Firefox
+```
+
 ## Issue tracker
 
 If you find a problem, please send us an email: kontakt@internet-czas-dzialac.pl