Add vegetarian dinner option

Change-Id: Ibcda53e07467957f12ccbaf5bc8dc02b9944365f
diff --git a/templates/register.htm b/templates/register.htm
index b62493e..c35dcf4 100644
--- a/templates/register.htm
+++ b/templates/register.htm
@@ -495,9 +495,13 @@
         <label class="form-label fw-bold" for="conference_dinner">Conference Dinner</label>
         <div class="form-group form-check">
             <input type="checkbox" class="form-check-input" name="conference_dinner" id="conference_dinner" <?php echo isset($_POST[ 'conference_dinner']) ? 'checked' : '' ?> oninput="update_total_due()" value="conference_dinner">
-            <label class="form-check-label fs-4" for="conference_dinner">I will be attending the conference dinner on 20 July at 8pm at the Rheinterrassen for the price of <strong>€&#160;<span id="conference_dinner_price"><?php echo $CONFERENCE_DINNER; ?></span></strong>.
+            <label class="form-check-label fs-4" for="conference_dinner">I will be attending the conference dinner on 20 July at 8pm at the <a target="iclc10-rheinterrassen" href="https://www.rheinterrassen.info/">Rheinterrassen</a> for the price of <strong>€&#160;<span id="conference_dinner_price"><?php echo $CONFERENCE_DINNER; ?></span></strong>.
             </label>
         </div>
+        <div class="form-group form-check pl-3" style="padding-left: 3.5em">
+            <input type="checkbox" class="form-check-input" name="vegetarian_dinner" id="vegetarian_dinner" disabled <?php echo isset($_POST[ 'vegetarian_dinner']) ? 'checked' : '' ?> oninput="update_total_due()" value="vegetarian_dinner">
+            <label class="form-check-label fs-4" for="vegetarian_dinner">I choose the vegetarian dinner option</label>
+        </div>
     </div>
 
     <label class="form-label fw-bold" for="participate">Lunch Options</label>