fix(docs): hljs depcrecation and new directive

couldn't figure out how to get hljs-vue to work so this was just the
easiest way to fix it

dashboard/src/directives/highlightjs.ts

@@ -0,0 +1,8 @@
+import Vue from "vue";
+import hljs from "highlight.js/lib/core";
+
+Vue.directive("highlightjs", {
+  bind(el, binding) {
+    hljs.highlightElement(el)
+  },
+});