Provide text for TTY off state

[anselmbradford]

The TTY drop-down is either TTY or blank. When clicking this it's not immediately clear that there are two entries possible, as the blank entry might just be padding on the drop-down menu.

Consider either:

• Using a checkbox for the TTY entry.
• Have the TTY off state say something like "Not Applicable" or "N.A."
• Have the TTY on and TTY off state say something like:
  • "NOT a TTY number"
  • "TTY number"