[BEAM-9916] Update I/O documentation links and create more complete I/O matrix

[epicfaace]

Update I/O documentation links to point to the appropriate pydoc / javadoc / godoc pages.

Also, create a more complete I/O matrix that has all the existing I/O's used in all three languages, with a tab to switch between languages, too. The matrix is now populated from the io_matrix.yaml file, as well.

R: @pabloem

The page now looks like this:

Additionally, I've also added links to the built-in I/O connector guides on the side bar, because previously they didn't exist:

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Post-Commit Tests Status (on master branch)

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

Pre-Commit Tests Status (on master branch)

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

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

[aromanenko-dev]

retest this please

[pabloem]

Thanks Ashwin, this looks really nice. I'll take a thorough look today, and hopefully merge or add comments.

[datancoffee]

Can we also add a section on "Applications" for application-specific connectors?

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Add a section "Applications" after the "Database" section but before "Miscellaneous"

FhirIO provides an API for reading and writing resources to Google Cloud Healthcare Fhir API.

https://github.com/apache/beam/blob/master/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/healthcare/FhirIO.java

HL7v2IO provides an API for reading from and writing to Google Cloud Healthcare HL7v2 API.

https://github.com/apache/beam/blob/master/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/healthcare/HL7v2IO.java

[pabloem]

FhirIO and HL7v2IO are not yet part of a release (they will be in 2.22.0 and 2.21.0 respectively), so we can skip that update for now. @jaketf will add them once their corresponding releases are out.

[pabloem]

I've merged your changes. They are really good. Thanks @epicfaace !
We need to follow up on

• FhirIO and HL7v2IO - @jaketf
• KuduIO and RabbitMqIO - @aromanenko-dev

[datancoffee]

FhirIO and HL7v2IO are not yet part of a release (they will be in 2.22.0 and 2.21.0 respectively), so we can skip that update for now. @jaketf will add them once their corresponding releases are out.

Sounds good. Thanks, Pablo!
New page looks much more readable than before (and can be extended with new sections)

[aromanenko-dev]

@epicfaace Thanks for working on this, now this doc part looks much better!