Enhanced README, focus on Nitro Users

[nwbrettski]

The readme is the entrypoint for Nitro users and clients, orbit chain operators, node operators, and Stylus engineers. The readme is the first touchpoint and should be viewed as a marketing tool not just technical documentation.

Issues:

• Poor navigation due to a lack of titles and content separation.
  • A documentation title with links to frequently requested or viewed pages such as, "run a node", "deploy an orbit chain", "build with Stylus".
  • Dedicated Contributing and Security sections, with simply links to existing pages.
• Missing Code of Conduct and Security tabs. (Not readme specific but visible tabs on the readme)
• Add some tags to provide more upfront information at a glance.
  • Go version, master branch CI status, release branch CI status, code coverage percentage.

Seeking better presentation and orientation for users and clients to help them get to the information that they need quicker.

[Kanasjnr]

@nwbrettski Is this issue still available to work on? If yes I will like to take it up

[gligneul]

Our documentation can be found at: https://docs.arbitrum.io/
The repo for documentation is: https://github.com/OffchainLabs/arbitrum-docs