Doc strings are missing on several functions.

[jmiah717]

Is your feature request related to a problem? Please describe.
It is more difficult to understand what functions are doing without the documentation strings.

Describe the solution you'd like
Add docstrings to several functions that are currently missing docstrings.

Describe alternatives you've considered
Leaving them as is.

Additional context
None needed, many functions do not have doc strings and I propose adding at least several of them in.

[jmiah717]

I have done a short PR to address some of these.
#721

[johnbumgarner]

Take a look at the usage documentation that I wrote for PyShark. LMK how I can improve the documentation to address how functions work.