Lightweight-mmm

What's Changed
- Plotting media contribution overtime has been added to plots.
- Plotting results from optimisation has been added.
- New utility for going from pd.DataFrame to our expected geo 3D array for geo models
- Expanded documentation of models.
- Improved workflows, CI and documentation
- Fixed edge case for certain tests
- Minor changes and fixes

**Full Changelog**: https://github.com/google/lightweight_mmm/compare/0.1.3...v0.1.4

What's Changed
- Improved workflows and documentation
- Fixed edge case for hill function
- Minor changes and fixes

What's Changed
- Add geo level models for bigger countries
- Adapt data scaling to accept geo data
- Adapt media optimization to geo models
- Adapt plots to geo level model and data
- Minor fixes and changes

What's Changed
- Fix install and import issues
- Add simple demo notebook
- Add control over seeds in `fit` and `predict` methods
- Minor changes and fixes

release
Initial base release.