Make comments form field resizable

[cmeury]

Observation

• On the write-review page, the comments input field is not resizable.

Expectation

• To enter longer texts it's usually convenient to have it resizable.

[mehmetbajin]

The idea was to disallow resizing to discourage lengthy reviews.

I am going to close this as a duplicate of #10 since the two are so intimately related.