Rework device page

Remove about topics template then replace it by guides,
support the project and usability section.

2 ideas behind these changes. Have an attractive device page.
Then introducing a usability section when we will list what is
working or not based on the tester feedback. See
`Feature & Usability` from https://devices.ubuntu-touch.io/device/fp3/
for example.

Close https://gitlab.e.foundation/e/backlog/-/issues/5810