[FLINK-11331][table][docs] Fix errors in tableApi.md and functions.md

[hequn8128]

What is the purpose of the change

This pull request fixes errors in tableApi.md and functions.md.

Brief change log

• Fix example errors in tableApi.md.
• Add the missing quarters and weeks udf in functions.md for java&scala

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)

[sunjincheng121]

Hi @hequn8128 Thanks for the PR.
I only left one suggestion that we can add the example in the doc. otherwise LGTM.

Bests,
Jincheng

[sunjincheng121]

We can add an example: e.g.:
E.g., 1.weeks returns 604800000 ms.

[hequn8128]

Good point!

[sunjincheng121]

Thanks for the update! @hequn8128
Add thanks for create the FLINK-11342. pretty cool!
this PR will be merged.
Bests,
Jincheng

[hequn8128]

@sunjincheng121 Thanks for the nice suggestion.
I create another issue to address the example problem of built-in udfs. I think it would be very helpful if we have example for every function. Looking forward to have your suggestions.

Best, Hequn

[sunjincheng121]

Merging...