[BUG] README fixes needed

[Tymmmy]

Steps to reproduce

1. Go to Readme page and make the following changes:

• Change the Rafiki definition to match the one from the Rafiki Repo

Current Test Network Readme:

Change the text to what is in the Rafiki repo Readme:

• Change the links from the New to Interledger, to be the same as the Rafiki Repo New the Interledger Section. Make sure all links work, especially the Interledger Specs point to https://interledger.org/developers/get-started/:

Expected result

Readme is fixed with correct description and working links

Actual result

Currently some links are broken or old. Description of Rafiki si better at Rafiki repo

Screenshots or videos

No response

Additional context

No response

Operating system

Windows

Operating system version

No response

Browsers

Firefox

Browser version

No response

[AntoineDeveloppeur]

Hello, please assign it to me. Job is done. Pull request #2020