Update Go templates according to Matt's new article

[matthyx]

I was really interested in using the tips and tricks from:
https://grafana.com/blog/2024/02/09/how-i-write-http-services-in-go-after-13-years/

And since oto was advertised there, I was hoping to see these implemented.

[StevenACoffman]

Hey, I've actually been really hoping that this happens as well!

That article's concludes with "Putting this all into practice":

This remains true even in cases where I use a code generation framework like our own Oto package to write the boilerplate for me based on templates that I customize.

So I hoped that func main() only calls run() and such would be demonstrated by the https://github.com/pacedotdev/oto/tree/main/example

I keep meaning to come back and make some PRs myself, but alas, other shiny objects keep distracting me.