Add more details and examples to the README

[MontrealSergiy]

GSOC preferred format is a detailed report or blog post. The github repo may be accepted but require a detailed README file, the current README file is rather short.

Would you mind expand it - maybe simply list the (sub) commands and options, maybe provide snapshots or examples?

Beside that

1. Could you mention that this is a GSOC 2025 project in the beginning of the README (could be bold font or go into a title)?
2. Please briefly mention what is CBRAIN in the first paragraph (see a CBRAIN paper, cbrain.ca, project proposal, GitHub Wiki or README)
3. In "Suitable for organizations wanting their own CBRAIN instance" replace "wanting" with 'that require' or 'which prefer to host CBRAIN themselves due to legal or corporate requirements' ...
4. You should mention that CI test were created by P.Rioux, and not to make excuse for failing tests (I still expect you will fix them), but to follow best open source practices that emphasise proper attribution. Could be something along lines :
   Continuous Integration (CI) tests and framework were initially configured by P. Rioux, providing automated validation of the codebase.

[Siddhant-Srivastava-20]

If no one is assigned on this PR kindly assign me on this.

[MontrealSergiy]

Please, go on