feat: better flags

pkg/invoice/report/assets/template.html

@@ -82,10 +82,14 @@
       <article>
         <div class="issue-title">
           <h3>
-            <span style="font-family: monospace">{{ .Shorthand }}</span>: {{
-            .Title }}
+            <a href="{{ .HTMLURL }}" style="font-family: monospace"
+              >{{ .Shorthand }}</a
+            >: {{ .Title }}
           </h3>
-          <p>Fertiggestellt: {{ .Closed | time }}</p>
+          <p>
+            {{ if .Closed }} Fertiggestellt: {{ .Closed | time }} {{else}} not
+            closed {{ end }}
+          </p>
         </div>
         {{ .CleanBody | md | oh 3 }}
       </article>