Migrate documentation to the main Chainloop repository

[danlishka]

Currently, we maintain our documentation in the separate Chainloop Docs repository.

By moving Chainloop docs to the main repository:

• We will simplify the process of updating documentation by integrating it with the new features' pull requests.
• We will encourage new contributions and indirectly improve the quality of our documentation.

We already have some docs in the main repo today.

### Tasks
- [x] add credentials
- [x] make the old deocs repo read only
- [x] merge code
- [x] make the deployment work again
- [x] update references in readme
- [x] update references raw.githubusercontent.com/chainloop-dev/docs
- [x] archive docs and update the README there
- [x] improve the deployment script