deploy stitching-headless on release and update readme (#277)

Author: lukasalexanderweber

.github/workflows/python-publish-headless.yml

@@ -2,7 +2,9 @@
 # with the new trusted publishing by https://github.com/marketplace/actions/pypi-publish
 name: Upload Python Package (headless)
 
-on: workflow_dispatch
+on:
+  release:
+    types: [published]
 
 permissions:
   contents: read

README.md

@@ -23,6 +23,13 @@ or `pip` to install `stitching` from
 pip install stitching
 ```
 
+for server (headless) environments (such as Docker, cloud environments etc.)
+use `stitching-headless`
+
+```bash
+pip install stitching-headless
+```
+
 ## Usage
 
 ### Python CLI