📚 Update copy and add information (#910)

* Update README.md

* Update README.md

* Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -119,6 +119,10 @@ To start n8n execute:
 npm run start
 ```
 
+To start n8n with tunnel:
+```
+./packages/cli/bin/n8n start --tunnel
+```
 
 ## Development Cycle
 
@@ -213,23 +217,7 @@ If you'd like to submit a new node, please go through the following checklist. T
 
 ## Extend Documentation
 
-All the files which get used in the n8n documentation on [https://docs.n8n.io](https://docs.n8n.io)
-can be found in the [/docs](https://github.com/n8n-io/n8n/tree/master/docs) folder. So all changes
-and additions can directly be made in there
-
-That the markdown docs look pretty we use [docsify](https://docsify.js.org). It is possible to test
-locally how it looks like rendered with the following commands:
-
-```bash
-# 1. Install docisify
-npm i docsify-cli -g
-
-# 2. Go into n8n folder (the same folder which contains this file). For example:
-cd /data/n8n
-
-# 3. Start docsificy
-docsify serve ./docs
-```
+The repository for the n8n documentation on https://docs.n8n.io can be found [here](https://github.com/n8n-io/n8n-docs).
 
 
 ## Contributor License Agreement