docs: Update hosted Phoenix tutorials to use register and add quickstarts (#4371)

* Convert answer_and_context_relevancy_llamatrace to use register

* Add .env to gitignore

* Move hosted phoenix example to the right folder

* Update hosted_phoenix_openai_tutorial.ipynb

Update tutorial to use register function

* Update hosted_phoenix_llamaindex_tutorial.ipynb

Update tutorial to use register function

* Add a header to the haystack tracing tutorial

* Added the evaluate rag with haystack tutorial

* rebasing fixes

* Update tracing_quickstart_openai.ipynb

* Addressing pr comments

* Update evals to generate inline

* Style fixes

* Fixing rebase merges

* Addressing PR comments

* style fixes