Workaround missing github alerts in pdoc

Author: Steve-Tech

pdoc/custom.css

@@ -0,0 +1,20 @@
+.pdoc .alert.tip {
+    color: #0a3622;
+    background-color: #d1e7dd;
+    border-color: #a3cfbb;
+    background-image: url("data:image/svg+xml,{% filter urlencode %}{% include 'resources/lightbulb.svg' %}{% endfilter %}");
+}
+
+.pdoc .alert.important {
+    color: #055160;
+    background-color: #cff4fc;
+    border-color: #9eeaf9;
+    background-image: url("data:image/svg+xml,{% filter urlencode %}{% include 'resources/exclamation-square-fill.svg' %}{% endfilter %}");
+}
+
+.pdoc .alert.caution {
+    color: #842029;
+    background-color: #f8d7da;
+    border-color: #f5c2c7;
+    background-image: url("data:image/svg+xml,{% filter urlencode %}{% include 'resources/exclamation-octagon-fill.svg' %}{% endfilter %}");
+}