Offchain worker to `latest` tag and maintain moving forward

[nuke-web3]

https://docs.substrate.io/how-to-guides/v3/ocw/transactions/ is presently broken and relies on monthly and external repos 😬

https://github.com/jimmychu0807/substrate-offchain-worker-demo is referenced now, but we need a stand-alone way that the devhub owns that is as low-manitainance as possible to integrate https://github.com/paritytech/substrate/tree/master/frame/examples/offchain-worker into any latest tagged node template.

[nuke-web3]

#773 unfortunately needs to have some things reverted for just this content ☹️

[jimmychu0807]

https://docs.substrate.io/how-to-guides/v3/ocw/transactions/ is presently broken and relies on monthly and external repos.

1. What is it means by "presently broken"?
2. So we always reference to devhub-latest in Substrate repo when referencing Substrate src now?

[nuke-web3]

1. The latest tag is untested, and your examples pin to a monthly that AFAIK is incompatible
2. Yes: devnhub/latest on upstream repos latest in all devhub repos