Create `Administration` section in the docs

[Ramiro Berrelleza]

Users of Okteto Scale and Okteto Enterprise have access to an administration panel. As part of the effort of making our docs more focused on the scenarios, instead of self-host vs SaaS, I think it's important to show case the 'Admin' features at the same level as 'Development Environments' and 'Preview Environments'.

This section should contain:

1. the admin dashboard (what today lives in https://www.okteto.com/docs/enterprise/administration/dashboard/)
2. Namespace cleanup (https://www.okteto.com/docs/enterprise/administration/cleanup/)
3. https://www.okteto.com/docs/enterprise/administration/private-repositories/github-app/
4. https://www.okteto.com/docs/enterprise/administration/private-repositories/ssh-key/
5. https://www.okteto.com/docs/enterprise/administration/volume-snapshots/ (we should break this into two sections, one on how to use it (using the values we use for cloud and scale), and one on how to configure it for self-hosted.
6. Cluster secrets

We now support a badge for 'Starter', 'Scale', and 'Enterprise'. We should also add 'SaaS' and 'Self-hosted' to the list of badges and properly label the pages according to what applies for SaaS (SaaS = okteto cloud + okteto for teams) and what applies for self-hosted