Add ability to create Comments on a person

[kgf]

Currently the Person and Comment models are linked, but there is no UI element to create a comment. There is UI to display them.
You should take a look at #272 and #565 for more details.
Any questions, please feel free to post them here.

[kgf]

@alexshook Do you have any interest in this one ?

[alexshook]

@kgf totally! Where would you want me to put the form to create comments?

[kgf]

@alexshook a blast from the past?

[alexshook]

Hey! Totally willing to restart this if you want, or take up something new if it's higher priority.

[kgf]

This would be a good one. I'd like to have the comments as a separate model so we know who made the comment, and when.
Thanks for your help!