Documentation clarity improvements in README

[JatHarshMalik]

In the README file, some documentation links are written as plain text URLs instead of formatted Markdown links. This can reduce readability and navigation for users.

Example:

Data integrations available can be found here: https://docs.openbb.co/python/reference

Suggestion: Convert them into Markdown links.

Example fix:

OpenBB Python Reference

This would improve readability and consistency across the documentation.

If needed, I would be happy to submit a pull request to fix these issues.