Move ArcGIS Tutorial into its own repo

[Florian-Katerndahl]

Currently, the ArcGIS tutorial is located inside the Remote-Sensing-at-FU-Berlin/Remote-Sensing-at-FU-Berlin.github.io` repo.

However, it should be contained in its own repo and added as a submodule similar to the qgis and planetary science series.

[Huaqo]

yes 1c1e724