Merge pull request #880 from ellerbrock/docker

add bash-it-docker to readme

README.md

@@ -36,6 +36,17 @@ fi
 
 Refer to the official [Bash documention](https://www.gnu.org/software/bash/manual/bashref.html#Bash-Startup-Files) to get more info.
 
+
+## Install using Docker
+
+You can try Bash-it in an isolated enviroment without changing any local files via a [Docker](https://www.docker.com/) Container.  
+(Bash Shell v4.4 with Bash-it, [bats](https://github.com/sstephenson/bats) and bash-completion based on [Alpine Linux](https://alpinelinux.org/)).   
+
+`docker pull ellerbrock/bash-it`
+
+Have a look at our [bash-it-docker respository](https://github.com/Bash-it/bash-it-docker) for further information.
+
+
 ## Update
 
 To update Bash-it, simply run: