readme: added docker hub url & sample cmd

README.md

@@ -0,0 +1,11 @@
+# docker container: ipfs daemon
+
+docker hub: https://hub.docker.com/r/fphammerle/ipfs/
+
+```sh
+sudo docker run --detach \
+    --cap-drop=all --security-opt=no-new-privileges \
+    --restart=unless-stopped \
+    --name ipfs \
+    fphammerle/ipfs:0.4.17-amd64
+```