chore: add mermaid diagram support (#3499)

Adding mermaid diagram support for the yellow-paper. 

# Checklist:
Remove the checklist to signal you've completed it. Enable auto-merge if
the PR is ready to merge.
- [ ] If the pull request requires a cryptography review (e.g.
cryptographic algorithm implementations) I have added the 'crypto' tag.
- [ ] I have reviewed my diff in github, line by line and removed
unexpected formatting changes, testing logs, or commented-out code.
- [ ] Every change is related to the PR description.
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this pull request to relevant issues (if any exist).

yellow-paper/docusaurus.config.js

@@ -36,6 +36,11 @@ const config = {
     locales: ["en"],
   },
 
+  markdown: {
+    mermaid: true,
+  },
+  themes: ["@docusaurus/theme-mermaid"],
+
   presets: [
     [
       "classic",

yellow-paper/package.json

@@ -19,6 +19,7 @@
   "dependencies": {
     "@docusaurus/core": "2.4.3",
     "@docusaurus/preset-classic": "2.4.3",
+    "@docusaurus/theme-mermaid": "^2.4.3",
     "@mdx-js/react": "^1.6.22",
     "clsx": "^1.2.1",
     "prism-react-renderer": "^1.3.5",