Enhancements for Documentation

[tareknaser]

• Crate-level documentation for each crate, with verbose explanations for crates that are meant to be published on crates.io.
• Ensure important structs like ResourceIndex have clear doc comments with API examples.
• Create CONTRIBUTING.md with guidelines:
  • Code Style Guidelines covering formatting, linting, and disallowing unused crate dependencies.
  • Document each crate, function, struct, and field consistently.
  • Consider test coverage and signing commits?
• Host high level documentation, possibly with mdbook.
• Clearly document ark-cli usage.
• Add ARK logo to the README.
• Display badges in the README for build status, code coverage, license, etc.,
• Add structured issue and pull request templates.