feat: Add an agent skill for working with setup chain

[esatterwhite]

This adds a skill that confirms to the agentskills.io spec. It should work with most any agent provider. It can be discovered by the skills.sh cli

This includes instructions on adding actions and functions, as well as some guidence on general usage.

Resolves: #135

[darinspivey]

if (opts, label) is the true default signature, perhaps the signature in number 1 should be (opts, _label) or (opts, label)?

[esatterwhite]

for number 1 - the label isn't passed to the actual action function, Thats only for defining the custom hook on the chain instance

[esatterwhite]

async myAction(arg1, arg2) {

}

vs

class MyChain extends Chain {
  myAction(arg1, ar2, label) {
    this.tasks.push(['myAction', label, arg1, arg2])
  }
}

[darinspivey]

maybe say here that the results are in chain.state.myAction and say what the value is.

In fact, we don't really talk about how to use chain.state, but I use it often when I don't want to assign the .execute's return val to a variable. Not sure where that should go, but I think somewhere.

[esatterwhite]

hmm. I have never used the internal state property directly. I tend to treat that as inside baseball / don't mess with it

[darinspivey]

you mean you always do chain.lookup('myAction')?

[esatterwhite]

yeah, use lookup, or the return value from execute(), mostly the latter

[esatterwhite]

The build fail is an old npm token problem. looking at it