Update readme

Author: sergeyklay

README.md

@@ -5,3 +5,11 @@
 
 An example project to show how to create release using GitHub Actions and PHP
 PHAR.
+
+Use this example if you have the following workflow:
+
+1. Creating a tag `git tag ...` && `git push --tags` should create a GitHub
+   Release from this tag
+2. You can use the web interface to manually create a GitHub Release
+3. When creating a GitHub Release (1 or 2 from above), the artifact should be
+   attached to release