docs[patch]: Add mermaid JS theme dependency to docusaurus (#14051)

- **Description:** Add mermaid JS dependency and configs to
documentation. Allows inline doc diagrams in markdown.
  - **Dependencies:** NPM package @docusaurus/theme-mermaid

docs/docusaurus.config.js

@@ -26,6 +26,11 @@ const config = {
   onBrokenLinks: "warn",
   onBrokenMarkdownLinks: "throw",
 
+  themes: ["@docusaurus/theme-mermaid"],
+  markdown: {
+    mermaid: true,
+  },
+
   plugins: [
     () => ({
       name: "custom-webpack-config",