Remove personal filter in docs dropdown

[klocke-io]

To reduce technical complexity and provide an easier ground for reasoning about the content structure, the persona filter should be removed from the documentation landing page, and for the time being, the only documentation we offer would be the current all.

• This would allow us to remove multiple workaround,s like the custom clickable dropdown
• The dataloading at runtime for the sidebar
• The hole filtering logic and more