doc: add data types to properties

[cjihrig]

Some of the docs specify the type for properties, while others do not. A good first contribution would be to update the properties that are missing this information. As an example, look at https://nodejs.org/api/process.html#process_process_connected vs. https://nodejs.org/api/child_process.html#child_process_child_connected. These two things represent the same concept, but the one in the child_process docs have the data type.

[tanujasawant]

@JungMinu Are you still planning on working on this issue? I am an Outreachy applicant and a newbie to Open Source. I have been visiting this issue with utmost excitement to see its outcome. Please comment if you're no longer interested.
Thanks!

[Trott]

I would request that people who already have contributions in the project please refrain from reserving new good first contribution issues. It makes the label considerably less useful for people looking for their actual first contribution.

(It's a bit different for a good first contribution issue that has been open for a while. If a good first contribution issue has been open for a few weeks, it's probably appropriate to remove the good first contribution label and submit a PR. But that's not the case here.)

[tanujasawant]

@Trott Forgive me, I was unaware of the fact that people might still be looking for first contributions. I'll look for other issues. Thanks!

[JungMinu]

@Trott Sorry, it was a mistake. I've just removed self-assignment

[imatveev]

Added most of values in pull-request

[imatveev]

Yet another pull-request

[imatveev]

Yet another pull-request