fix: a few REVOLT_PUBLIC_URL references needed cleanup

[Docteh]

Specifically REVOLT_PUBLIC_URL is for the api, so for these examples should end in /api

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[DeclanChidlow]

Happy with the changes to include /api, but am unsure about the guidance of using the config script. I imagine that most people referring to the additional notes probably have manual configs. They also might not have OpenSSL installed. I'm not sure that it is a necessary change.

[Docteh]

I can take it out, I think I put that in there after reading someone basically would have been happy running it, but didn't know about the script because they skipped the whole section on hostinger.

Yeah just say so and I'll update the PR

[insertish]

Duplication is fine here.