feat: add 'coming soon' empty state for projects page & gitignore public dir

- Add animated coming-soon card when no projects exist
- Add Grafana shortcode and gebrauchtwagen-datenbank project
- Add hugo/eliaskohout.de/public/ to .gitignore and remove from tracking

hugo/eliaskohout.de/layouts/_default/list.html

@@ -5,19 +5,28 @@
     <h1>{{ .Title }}</h1>
 
     <div class="project-grid">
-      {{ range .Pages.ByDate.Reverse }}
-        <a href="{{ .RelPermalink }}" class="project-card">
-          {{ with .Params.image }}
-            <img src="{{ . }}" alt="{{ $.Title }}" />
-          {{ end }}
-          <h2>{{ .Title }}</h2>
-          <p class="tags">
-            {{ range .Params.tags }}
-              <span class="tag">{{ . }}</span>
+      {{ if .Pages }}
+        {{ range .Pages.ByDate.Reverse }}
+          <a href="{{ .RelPermalink }}" class="project-card">
+            {{ with .Params.image }}
+              <img src="{{ . }}" alt="{{ $.Title }}" />
             {{ end }}
-          </p>
-          <p>{{ .Params.summary }}</p>
-        </a>
+            <h2>{{ .Title }}</h2>
+            <p class="tags">
+              {{ range .Params.tags }}
+                <span class="tag">{{ . }}</span>
+              {{ end }}
+            </p>
+            <p>{{ .Params.summary }}</p>
+          </a>
+        {{ end }}
+      {{ else }}
+        <div class="coming-soon">
+          <span class="coming-soon-icon">🚀</span>
+          <h2>More projects coming soon</h2>
+          <p>I'm currently working on new things — stay tuned!</p>
+          <span class="coming-soon-dots"><span>.</span><span>.</span><span>.</span></span>
+        </div>
       {{ end }}
     </div>