Update 'README.md'

README.md

@@ -1,2 +1,14 @@
-# Docker.Containers.GitSparseClone
+# Docker.Containers.GitSparseClone [![Build Status](https://ci.spamasaurus.com/api/badges/djpbessems/Docker.Containers.GitSparseClone/status.svg)](https://ci.spamasaurus.com/djpbessems/Docker.Containers.GitSparseClone)
+Useful as a Kubernetes-sidecar container that downloads files from a git-repository to a Kubernetes-volumeMount, which other containers can then also mount and use.  
 
+### Usage:
+```  
+docker run -it \
+    -e SPARSE_CHECKOUT=<filter> \
+    -e REMOTE_REPO=<url> \
+    -e REMOTE_BRANCH=<branch> \
+    -e TARGET_DIR=<path> \
+# Optional
+    -e FLATTENFOLDER=true \
+-d djpbessems/git-sidecar
+```