feat: update example creation instructions

[SgtPooki]

I think instead of having users attempt to create an example repo under the ipfs-examples org, we should instead redirect them to the ipfs-examples/github-mgmt repo and have them create a PR for the new repository there, in addition to the PR to this repo for adding the example subfolder.

What do you think @achingbrain @galargh ?

[galargh]

Yes, you can totally create repos through github-mgmt. You can even automatically initialise them if you set auto-init: true.

[galargh]

I haven't tried that but it should also be possible to automatically initialise the repo using a specific template. See template param.