Update contributing docs now that v5 is fully released (#3500)

* Remove "development version" note from docs

No longer applies now that V5 is fully released

* Remove 'beta' note and add link to GFP issues

GFP = Good First Pick

CONTRIBUTING.md

@@ -17,8 +17,6 @@ In order to set up this project and start contributing follow this step by step
     $ git clone git@github.com:<your-username>/webdriverio.git
     ```
 
-    _Note_: this is currently a dev repository to keep making releases in the [original](https://github.com/webdriverio/webdriverio) project. Once we are at a state where this can be released we will force push this master branch to the webdriverio/webdriverio#master branch.
-
 * Switch to Node v8 (you should be able to use older/newer versions of Node but we recommend to use v8 so all developers are on the same side)
 
 * Setup project:

README.md

@@ -35,9 +35,9 @@ WebdriverIO is a test automation framework that allows you to run tests based on
 
 ## Contributing
 
-Check out our [CONTRIBUTING.md](CONTRIBUTING.md) to get started with setting up the repo. This repository is a development repository for the new version.
+Check out our [CONTRIBUTING.md](CONTRIBUTING.md) to get started with setting up the repo.
 
-We are trying to put up a proper roadmap for the beta release. Until then please reach out in our [Gitter Channel](https://gitter.im/webdriverio/webdriverio) if you have question on where to start contributing.
+If you're looking for issues to help out with, check out [the issues labelled "good first pick"](https://github.com/webdriverio/webdriverio/issues?q=is%3Aopen+is%3Aissue+label%3A"good+first+pick"). You can also reach out in our [Gitter Channel](https://gitter.im/webdriverio/webdriverio) if you have question on where to start contributing.
 
 ## Packages