[BEAM-12675] Fix issue with language switcher on hadoop page

[pcoet]

Please add a meaningful description for your change here

@aaltay
@tysonjh

This fixes an issue with the language switcher display on the Hadoop page. The JavaScript and CSS are making some assumptions that they shouldn't be making, but I don't think it's worth getting into that right now, since there's a workaround. Feel free to cut a ticket to me if this seems like a problem.

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ValidatesRunner compliance status (on master branch)

Lang	ULR	Dataflow	Flink	Samza	Spark	Twister2
Go	---					---
Java
Python	---					---
XLang						---

Examples testing status on various runners

Lang	ULR	Dataflow	Flink	Samza	Spark	Twister2
Go	---	---	---	---	---	---	---
Java	---		---	---	---	---	---
Python	---	---	---	---	---	---	---
XLang	---	---	---	---	---	---	---

Post-Commit SDK/Transform Integration Tests Status (on master branch)

Go	Java	Python

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website	Whitespace	Typescript
Non-portable
Portable	---			---	---	---

See .test-infra/jenkins/README for trigger phrase, status and link of all Jenkins jobs.

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI.

[ibzib]

It looks like there are potentially a lot more instances of this. https://gist.github.com/ibzib/efaeb9e737a7b96cf034cb5aa2a2b25c

What would we need to do to fix the root cause?

[pcoet]

Ah, okay. Let me look into it some more. The class attributes are not getting set correctly on the snippets without the extra return, which is probably because the DOM tree is a little different for those snippets. The jQuery selector probably needs to be a little more flexible. Will investigate...

[pcoet]

It will be non-trivial to fix the root cause. The Markdown parser is generating extra <p> tags for the newline between highlight shortcodes, and that breaks scripts and CSS. I created another ticket for that root issue: https://issues.apache.org/jira/browse/BEAM-12688 However, I'm not sure that it's even worth fixing. I'll go through the pages and clean them up manually first: https://issues.apache.org/jira/browse/BEAM-12689 In the meantime, I think we should merge this PR.

[ibzib]

Thanks for looking into this further.

LGTM

[aaltay]

Thank you!