Add support for disabling few website features

[Neverous]

This adds build time toggles for disabling:

• Features cards - seems mostly like an ad, not really useful in custom deployments and can be confusing to users (great on the official one though to learn what this project is :+1:)
• "One-click link" - disabling it makes for easier enforcement of using multiple communication channels when sharing secrets

[DracoBlue]

Hey @jhaals!

What do you think about those changes?

For our deployment we need to be able to disable the "one-click" link - thus this PR would also fix me use case :).

Best regards

[donserdal]

Hey @jhaals! Would love to see this in the official release!