feat: add a placeholder video to the homepage

[ChasNelson1990]

Description

Uses the insights block to add a video. The idea is that the client will replace this with an introduction to the repository, ideally featuring the minister or somebody high up.

closes fjelltopp/zarr-ckan#146

On laptop:

On phone:

Internationalisation and Localisation

Strings are i18n friendly but not translated. This is probably fine for this client.

Checklist

• The GitHub ticket for this issue has been updated to "Ready to Review" or equivalent.
• I have developed these changes in discussion with the appropriate project manager.
• My code follows the general Fjelltopp documentation (see Confluence).
• I have made corresponding changes to the Fjelltopp documentation (see Confluence).
• I have rebased this branch with master.
• New dependency changes have been committed.
• I have added automated tests that prove my fix is effective or that my feature works.
• New and existing tests pass locally with my changes.
• My changes generate no new warnings.
• I have performed a self-review of my own code.
• I have assigned at least one reviewer.
• I have assigned at least one label to this PR: "patch", "minor", "major".

[A-Souhei]

Looks good to me.