Documentation files added to the docs folder

[AnumDastgir]

1. Created a new file for "Hooks".
2. Moved the other docs files like Configuration and Customization and Develop.md files to the Docs file, to gather all the docs and instructions at one place.

After this is approved, I'll change the links to all these files (who have been moved from their directories to the 'Docs' folder.

[schrieveslaach]

Thanks for restructuring the documentation. From my point of view we should include following changes:

• The links pointing to the files (e.g. to Develop.md) should be adjusted in the same merge request
• Rename configurationInstructions.md to configuration.md

[schrieveslaach]

We should keep the headline and point to the hooks files as the document does for companions.