Preparing `rsxml` module for PyPi deployment

In order to publish our rsxml we need our best foot forward. That includes metadata, help, readmes etc.

Here's what we need:

[x] A good Readme: Introduction. why you need this, installation, basic usage, where to go for help, link to examples folder in the repo.
[x] A CHANGELIST.md file we link to from the readme. It can be empty to start.
[x] Need a LICENSE file. MIT license is probably fine.
[x] Improvements to metadata (pyproject.toml and setup.py) (see docs)
[x] More python examples (especially for the XML writing stuff)
- [x] Better comments on examples to let people know why we're doing every step.
- [x] Different use cases: (i.e. here's how you create a NEW xml, here's how you update an existing one)
[x] A thought to versioning. What version should we start with?
[x] @philipbaileynar please make a PyPi account so that I can add you to the project

Resources

A good example of a package the looks good are:

You can probably steal a lot of config and ideas from them.