Problem: installation guide for devs has too much information

Solution: restructure the installation guide and make it more usable

The [Installation Guide for Developers](https://docs.bigchaindb.com/projects/py-driver/en/latest/quickstart.html#installation-guide-for-developers) needs to be updated and improved.
First of all it is not only an installation guide which is misleading. It is actually a guide to interact with github.
The guide can be merged with [Installing from the Source Code](https://docs.bigchaindb.com/projects/py-driver/en/latest/advanced-installation.html).
The guide needs to have a new name and needs to be restructured. It's fine to explain the whole process to get the repository and how to commit+push it when changes were made. But additional to that we need to show how to set up the dev environment properly.

To Do:
- [ ] Don't link to `Advanced Installation Options` just move it to the section (this should not just be advanced, but also the guide for devs, but only for installation(!)
- [ ] Instead of cloning we should tell developers to fork, linking to the GitHub forking example should be good enough
- [ ] Remove all steps after a successful installation and link to the Contributing section instead
- [ ] Update [Installing the Driver](https://docs.bigchaindb.com/projects/py-driver/en/latest/quickstart.html#installing-the-driver) to include the way to install alpha, beta, etc: [example](https://docs.bigchaindb.com/projects/py-driver/en/master/readme.html#install)
- [ ] add `pre-commit` setup after the installation of the dependencies [example](https://docs.bigchaindb.com/projects/contributing/en/latest/dev-setup-coding-and-contribution-process/write-code.html#start-writing-code)

Open for comments/discussion/better ideas

Review the Installation Guide for Developers, Installing from the Source Code, Installing the Driver, and the linked Contributing and write-code pages. Consolidate the installation and development setup guidance, clarify the guide's name and scope, include fork and pre-commit steps, and link completed contributors to the Contributing section; done means all checklist items are addressed without duplicated or misleading instructions.

Written by the indexing model from the issue text.