Sparse Documentation: node module

[garbagetrash]

Update documentation for the node module. In particular:

• Add single line descriptions where missing, and extended descriptions where necessary
• Add arguments sections where missing
• Add examples sections where missing
• Ensure all docs tests are passing

Use the util module documentation (or better) as a target for level of completeness.

[garbagetrash]

Probably not much for you to do on this one since there aren't too many pieces to be documented, but I figured it'd be best for you to look at it rather than me since you know the guts so much better.