fix(staff_create): require staffid field (#145)

src/invenflask/templates/staff_create.html

@@ -63,6 +63,7 @@ <h1>{% block title %} Create Staff {% endblock %}</h1>
               placeholder="Staff ID"
               value="{{ request.form['staffid'] }}"
               autocomplete="off"
+              required="required" 
               onkeypress="return runScript(event);"></input>
        <!-- <input type="checkbox" id="staffgen" name="staffgen"/>
        <label for="staffgen">Auto Generate Staff ID</label>        -->