allow customizing commit messages

[stefanprobst]

when using github storage mode, it would be great to be able to customize the commit messages.

i think these are currently set here and here.

[stefanprobst]

would you accept a pr to support an additional storage config option?

{
  kind: "github",
  repo: { owner: "stefanprobst", name: "keystatic-test" },
  commitMessages: {
    update({ path }) {
      return `content: update ${path}`
    },
    delete({ path }) {
      return `content: delete ${path}`
    },
  }
}

see https://github.com/stefanprobst/keystatic/commit/23e2f75ede7097c683b89c7a7fed86372b488361

[ducan-ne]

+1 for this, I want to skip add prefix "[CI Skip]" to skipping CI build, unnecessary build About api. I only need something like this

{
  kind: "github",
  repo: { owner: "stefanprobst", name: "keystatic-test" },
  commitMessageTemplate: '[CI Skip] Update {{path}}'
}