Code quality/project standards alignment

[woodruffw]

Similar to https://github.com/crytic/slither/issues/2096.

This is a meta-issue, intended to track sub-issues that will align tealer's codebase, development practices, etc. with the rest of our public tooling.

• [ ] Align README.md with our doc practices
• [ ] Modernize the Python codebase
  • [ ] Switch to pyproject.toml (currently exists, but the build is in a separate setup.py)
  • [ ] Use pypa/build for the build (sdist and wheel(s))
  • [ ] Use ruff?
• [ ] Track Python dependency upgrades via dependabot.yml
• [ ] Add some kind of QUICKSTART.md or similar guide (broken out from the current README.md)

(This list is not intended to be exhaustive, and will be updated over time!)