more customization options

[piedoom]

Allow the user to change the header image/video or remove it all-together

[piedoom]

Re-targeting this issue since the header no longer exists. Certain customization options should be present:

Necessary:

1. Ability to show a header image
2. Ability to customize navigation, add custom links

Useful:

1. Ability to select only light or dark mode

[piedoom]

Done with ability to select just light or dark