Setup packaging to meet Scientific Python structure

[lsetiawan]

Overview

Need to port over the package structure to follow the Scientific Python Library Development Guide

Action Items

• Move codebase to be under src directory #2
• Update build frontend to use hatch #3
• Change test directory name from test to tests #4
• Update python-app.yml to ci.yml to be more explicit #5
• Add cd.yml for automated wheel building and pushing to pypa #6
• Add .github/dependabot.yml for updating github actions versions #7
• Add .pre-commit-config.yaml for setting up pre-commit #8
• Add .readthedocs.yml for hosting documentation on ReadTheDocs #9
• Add noxfile.py for easy setup or build of package #10
• Update the README.md to include badges, buttons, and improved instructions+ #20
• Update caustic package name to caustics #24