Add two categories to Geo group

Hi team,

Currently, the Geo group does not contain any categories; however, Geo is used for two distinct purposes by our customers:

1. Geo-replication
2. Disaster recovery.

I arrived at this conclusion using qualitative data speaking to customer success, support, the sales organisation and the Geo group. I will validate these assumptions further in direct customer interviews. Our documentation also clearly states that Geo can be used for Disaster Recovery.

At this moment, there is no clear distinction in product strategy, nor is it possible to track maturity for those two capabilities separately. According to our category definition, categories could be individual products in other companies. In my view, this is the case here and by adding these categories for Geo it will be easier to define individual product strategies and to decouple those two categories. This will also allow us to communicate our capabilities more clearly to customers, who may be more interested in one or the other.

This MR modifies the categories.yml and stages.yml file to add a first iteration of those two categories. It also modifies the Geo group page to link to the two underlying category strategies. The Geo group strategy requires further work.

To push this change, I have also compiled a package of related MRs that are needed to make this change happen. Each MR can be reviewed and discussed individually:

1. MR for the Geo-replication strategy: !23882 (merged)
2. MR for the Disaster recovery strategy: !23961 (merged)

Both strategy pages use the updated category strategy page template. Both strategies are, as usual, work in progress and some sections require additional work. I do feel that this work is at a point where a review and potential is useful before iterating further.