Inconsistent proper noun status for "Minimal APIs"

[guardrex]

@tdykstra @wadepickett ... I think it's supposed to be a proper noun everywhere: "Minimal APIs" not "minimal APIs" when referring to the ASP.NET Core framework feature. It looks like its 60-40 or 70-30 split in favor of proper nouns.

I'll mark myself to make a pass and update to proper nouns everywhere; but of course, plz feel free to take it over if one of you wishes to do the work.

UPDATE: Well ... I'll do it now. I think you guys are still 🛌😴💤😆. I'll ping u for review.