Add CSS Variables for Menu

[myleskeeffe]

Add CSS Variables for Menu - Fallback value is as default (primary-text-color and primary-background-color). This allows for the menu to have a color/background that is decoupled from the main pages color/background.

Proposed change

Creates CSS variables for the menu's background & text colour (the part which contains the hamburger menu icon). This allows for these to be specified separately, and not be the same as the main pages.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Code quality improvements to existing code or addition of tests
• Breaking change (fix/feature causing existing functionality to break)

Example configuration

Additional information

For example:
From:

To:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

[homeassistant]

Hi @myleskeeffe,

It seems you haven't yet signed a CLA. Please do so here.

Once you do that we will be able to review and accept this pull request.

Thanks!