Categorise data types for Geo

In the limitations section of the documentation, we list out all of the data types that GitLab uses. https://docs.gitlab.com/ee/administration/geo/replication/#limitations-on-replicationverification Valery also helpfully provided more context to each which was captured in the Geo Discussion doc here: https://docs.google.com/document/d/18vGk6dQs7L0oGQOb_bNiFa5JhwLq5WBS7oNxQy09ml8/edit#heading=h.umcqkt7k7tic

We need to categorise these groups of data to help support building a framework for managing all data types with Geo.

The output of this issue should be updated documentation with a category column, along with further information added to the notes column.

For example,

Category Data Type
Repository Project
Repository Wiki
Repository Designs
LFS LFS Objects
LFS Uploads
LFS CI Job Artifacts
Edited Nov 05, 2019 by Fabian Zimmer
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