Fix link prefix for homepage

[ericswpark]

If the user supplies a http/https prefix then the homepage link breaks because of it. Do not supply a prefix and let the user choose.

[OJFord]

Thanks, but dupe of #126.

[ericswpark]

@OJFord do you know when it'll be merged (or if @posquit0 is maintaining this repo at all)? The PR seems to be stuck for the last 7 years...

[OJFord]

Posquit0 added me to help with the workload, but unfortunately I don't spend a lot of time on it either - I've had a couple of big clear outs and tried to stay on top of new requests (especially just closing down / moving to discussions) the spurious or unrelated stuff, which frankly is the bulk of it, but I haven't been able to get through a lot of the backlog of genuinely useful work or suggestions.

Since it seems the author there has moved on, I will either merge as is or apply my suggestion myself. I'm just always cautious to test manually any changes myself since I don't cause inadvertently 'breaking changes' (in this context really any changes to style or layout with existing use of the class unchanged) in people's CVs.