Thinks to be adjusted after registration of EMB

The following changes have to be incorporated once EnergyModelsBase (EMB) is registered:

[x] Update the file README.md (Badge for CI, removal of Note)
[x] Update the file examples/README.md,
[x] Add GitHub CI based on the same files as in EMB,
[x] Remove Pkg.add(url="https://github.com/EnergyModelsX/EnergyModelsBase.jl") from the documentation.yml file,
[x] Update the Quick start page in the documentation, and
[x] Add EnergyModelsGeography to the Project.toml for simplified local build of the documentation.

EnergyModelsX / EnergyModelsGeography.jl