Updated snippets in README

Author: andersevenrud

README.md

@@ -30,15 +30,15 @@ Visit the [official demo](https://demo.os-js.org/) for a preview version. Please
 
 You can run a demo using Docker without checking out any source-code:
 
-```
+```bash
 docker run -p 8000:8000 osjs/osjs:latest
 ```
 
 ### Custom
 
 Clone the master branch of the official OS.js repository:
 
-```
+```bash
 git clone -b master --single-branch https://github.com/os-js/OS.js.git
 cd OS.js
 ```
@@ -49,15 +49,15 @@ You can run OS.js locally without installing anything on your host system if you
 
 Simply run the following command and a complete environment will be set up for you:
 
-```
+```bash
 docker-compose up
 ```
 
 #### Locally
 
 To install directly on the host system you'll need Node 10 (or later).
 
-```
+```bash
 # Install dependencies
 npm install