Add README for bor module

[Raneet10]

Description

This PR adds a README for bor module.

Changes

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)
• Changes only for a subset of nodes

Checklist

• I have added at least 2 reviewer or the whole pos-v1 team
• I have added sufficient documentation in code
• I will be resolving comments - if any - by pushing each fix in a separate commit and linking the commit hash in the comment reply

Testing

• I have added unit tests
• I have added tests to CI
• I have tested this code manually on local environment
• I have tested this code manually on remote devnet using express-cli
• I have tested this code manually on mumbai
• I have created new e2e tests into express-cli

[codecov]

Codecov Report

All modified lines are covered by tests ✅

see 1 file with indirect coverage changes

📢 Thoughts on this report? Let us know!.

[manav2401]

Noice, LGTM. Just a few suggestions.