This PR:
- supersedes https://github.com/ComposioHQ/composio/pull/3535 and
credits @eldar702 for the original `CONTRIBUTING.md` refresh
- closes https://github.com/ComposioHQ/composio/issues/3487
- refreshes the repo layout around `ts/`, `python/`, `docs/`, and root
release/install tests
- documents the current `mise.toml` toolchain and removes stale
Corepack, `.nvmrc`, `.bun-version`, and top-level `packages/` guidance
- replaces the strict file-header requirement with current
TypeScript/Python coding standards
- adds current TypeScript e2e, Python, docs-site, changeset, and
release-doc pointers
- verifies documented paths, package scripts, Python make targets,
Prettier, and whitespace checks locally
Co-authored-by: Eldar Shlomi <eldarshlomi7@gmail.com>