Updated some of the CPython feature differences:
- Updated status of some features.
- Added CSS to fix table widths to 100% and word wrap.
- Specified explicit table column ratios to improve layout appearance.
- Added missing references to anchors.
- Better consistency with use of formatting and case.
And how they relate to MicroPython. As these features are implemented (or
the decision is made to not implement them) the tables can be updated to
document the differences between MicroPython and standard Python.
