Improve readability and wording

[aitestino]

Corrected typos, sentence structure, and overall added clarity.

[GerriorL]

Thanks for taking the time to edit the documentation! However, in this case since "testscript" and "testcase" are in reference to internal classes they should be left as is.

[mjbear]

@GerriorL @aitestino
Do we want to capitalize Testcase or Testscript?

Similar as to was done here (but probably without adding the back ticks for inline code).
https://github.com/CiscoTestAutomation/pyats/pull/172/files#diff-9151667b9761d14c0d878feb1a7493271163d038dc15019ed2613ba0fc33e199R349

[GerriorL]

@GerriorL @aitestino Do we want to capitalize Testcase or Testscript?

I think that would be for the best

[mjbear]

@aitestino
These are some great clarity improvements!

Apologies for the likely flood of GH emails. I started by using the webui code review feature and I really should have gone the distance and submit a pull request to you. (That's what I'm doing now as aitestino#1.)

[mjbear]

I agree with the change on this line.
Here this is not a code object, but instead a normal English noun.

[mjbear]

@GerriorL
Updates have been made.
Thank you for reviewing them when you have time!