Resolve "Extra work "reason" not limited in length"

Closes #204 (closed)

src/main/resources/static/js/main.js

@@ -327,7 +327,7 @@ function declarationSubmit() {
     } else if (isDurationGreaterThanRemainder(timeEl.value)) {
         document.getElementById("new-declaration-time-remaining-error").classList.remove("hidden");
         timeEl.focus();
-    } else if (reasonEl.value == null || reasonEl.value === "") {
+    } else if (reasonEl.value || reasonEl.value.length < 10 || reasonEl.value.length > 140) {
         document.getElementById("new-declaration-reason-error").classList.remove("hidden");
         reasonEl.focus();
     } else {