[BEAM-1251] Add a link to Python 3 Conversion Quick Start Guide to the list of ongoing efforts on Beam site.

[tvalentyn]

---

Follow this checklist to help us incorporate your contribution quickly and easily:

• Format the pull request title like [BEAM-XXX] Fixes bug in ApproximateQuantiles, where you replace BEAM-XXX with the appropriate JIRA issue, if applicable. This will automatically link the pull request to the issue.
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Post-Commit Tests Status (on master branch)

Lang	SDK	Apex	Dataflow	Flink	Gearpump	Samza	Spark
Go		---	---	---	---	---	---
Java
Python		---			---	---	---

[tvalentyn]

Hey @swegner, am I using a correct way to change the Beam-site? Thanks.

[swegner]

Yup!

If you pop open the "All checks have passed" bar, you'll see a link to the "Website_Stage_GCS" job results, which contains a link to your staged changes for review: http://apache-beam-website-pull-requests.storage.googleapis.com/6679/index.html

(I'm brainstorming a way to make that link more prominent on GitHub; let me know if you have ideas)

[tvalentyn]

@swegner we can explore a possibility to add a link to staged website to the PR template. Also https://help.github.com/articles/creating-a-pull-request-template-for-your-repository/ says it may be possible to have multiple pull request templates. Maybe we could have a separate template for site changes, but then unclear what template should have a PR that touches both SDK and site.

[tvalentyn]

r: @aaltay

[swegner]

@tvalentyn I had looked into the possibility of multiple templates. However it appears that the workflow for selecting a pull request requires using a special pull request URL with query parameters (docs). I don't like the idea of requiring contributors to mess with URLs to open a PR.