feature request: support for Umami analytics

[marten-seemann]

Feature Description

It would be nice if there was out-of-the-box support for Umami analytics.

Problem/Solution

Umami is a self-hosted analytics solution with arguably much better privacy properties than Google Analytics.

Alternatives Considered

I could modify the template myself to include the required JavaScript. However, this seems like a useful feature to have for a larger number of users, and it would be nice if Umami support could be enabled by simply configuring it in the config.

[ahgraber]

+1

[imfing]

@ahgraber Hi, you can try out

#328 (comment)

before #328 gets merged