[Doc] [wip] Add dev workflow page

[architkulkarni]

Why are these changes needed?

Adds a page describing a development workflow for Serve applications.

Related issue number

Checks

• [ ] I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• [ ] I've run scripts/format.sh to lint the changes in this PR.
• [ ] I've included any doc changes needed for https://docs.ray.io/en/master/.
• [ ] I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • [ ] Unit tests
  • [ ] Release tests
  • [ ] This PR is not tested :(

[architkulkarni]

@shrekris-anyscale @edoakes @sihanwang41 @simon-mo This is still rough, but is ready for an initial content review.

I've left some questions and comments as "TODOs" that I need to resolve, but if you know the answer off the top of your head feel free to comment it. The code sample doesn't work at the moment, I think I'm doing something wrong with the ClassNode.

As a more general point, I don't know whether it's better to use serve.run(..bind(bind()) or to use dag.execute here. The two methods (dynamic dispatch with passing deployments into each other, vs. InputNode() call graph) don't seem compatible, in the sense that you wouldn't start with one of them for dev and switch to the other one for prod (you could, but you'd be rewriting a lot of code.)

[edoakes]

@architkulkarni you have DCO and lint failures

[architkulkarni]

@stephanie-wang Thanks for the review! Addressed/responded to the comments, could you please take another look?