doc: update Readme files
Non-critical PR
I want to add more information in the repository doc to help developers contribute to the project and understand how the datasets-server works.
Pending tasks:

- [x] Update Readme.md files with their respective ENV variables
- [x] Add a general architecture diagram (Maybe in main Readme.md)
doc: update Readme files: Non-critical PR
I want to add more information in the repository doc to help developers contribute to the project and understand how the datasets-server works.
Pending tasks:

- [x] Update Readme.md files with their respective ENV variables
- [x] Add a general architecture diagram (Maybe in main Readme.md)