feat: add shortcode to embed html

This was implemented to embed drawio exports

layouts/shortcodes/html.html

@@ -0,0 +1,13 @@
+{{ $source := index .Params 0 }}
+
+{{ with .Page.Resources.GetMatch $source | readFile }}
+{{ .|safeHTML }}
+{{ end }}
+<style>
+    /* Reset the image width that is set in the theme
+    If wired styling issues appear, check if the theme is responsible and eventually unset this here
+    */
+    img {
+        width: unset;
+    }
+</style>