:memo: Added notation on distance parameter

frontend/src/entities/survey/survey.answer.validator.js

     pronouns: Joi.string(),
     language: Joi.string(),
     image: Joi.any(),
+    // TODO: specific distance units needed to be inputted within this field
+    // (i.e. km, mi, etc.) ... or just change the way the distance component
+    // works.
     distance: Joi.string(),
     blurb: Joi.string().max(200),
     value: Joi.string(),