Footer link to Stirlingpdf.com (#1827)

* fix

* remove donate

* Footer to have link to website

---------

Co-authored-by: a <a>

src/main/resources/templates/fragments/footer.html

@@ -10,7 +10,8 @@
 
     <!-- powered by section -->
     <div class="footer-powered-by">
-      <span th:text="#{poweredBy} + ' Stirling PDF'"></span>
-    </div>
+	  <span th:text="#{poweredBy}"></span>
+	  <a href="https://stirlingpdf.com" class="stirling-link">Stirling PDF</a>
+	</div>
   </div>
 </footer>

src/main/resources/templates/fragments/navbar.html

@@ -397,11 +397,6 @@
               <a href="https://discord.gg/Cn8pWhQRxZ" class="mx-1" role="button" th:title="#{joinDiscord}">
                 <img th:src="@{'/images/discord.svg'}" alt="discord">
               </a>
-              <a href="https://github.com/sponsors/Frooodle" class="mx-1" role="button" th:title="#{donate}">
-                <span class="material-symbols-rounded fill footer-icon" style="font-size: 2.5rem;">
-                  favorite
-                </span>
-              </a>
             </div>
 
             <a th:href="@{'/swagger-ui/index.html'}" class="btn btn-sm btn-outline-primary mx-1" role="button"