Reviewer Registration: update certain field descriptions

[racheljsmart]

There is a case of PCs adding the review form json to the field "Additional Reviewer Form Options" in the reviewer registration. The description is essentially the same as what's in the Review Stage for the "Additional Review Form Options". Perhaps rewriting this description will limit any confusion about whether PCs are setting the review form in the reviewer form if they are setting up the registration form before the review form.

Current description:

Configure additional options in the review form. Use lowercase for the field names and underscores to represent spaces. The UI will auto-format the names, for example: supplementary_material -> Supplementary Material. Valid JSON expected.

Alternative description:

Configure additional options in the reviewer registration form. Use lowercase for the field names and underscores to represent spaces. The UI will auto-format the names, for example: student_author -> Student Author. Valid JSON expected.