chore: add example page markdown

Author: pdmnyberg

EXAMPLE.md

@@ -0,0 +1,19 @@
+# Training Metrics Databse widget example
+
+## Metrics widget
+
+<div id="tmd-widget-container"><div>
+<script src="https://elixir-europe-training.github.io/Training-Metrics-Database-widget/widget.js"></script>
+<script>
+  TMDWidget({
+    container: "#tmd-widget-container",
+    question_sets: [
+        "quality",
+        "impact",
+        "demographic"
+    ],
+    endpoint: "https://tmd-test.elixir-hpc.si/metrics"
+  }).catch((error) => {
+    console.error('TMDWidget failed to initialise', error);
+  });
+</script>