Remove external stylesheets and JS libs.

markdown.css is inlined and seems to be enough anyway.

--- a/not1mm/data/not1mm.html
+++ b/not1mm/data/not1mm.html
@@ -1,12 +1,6 @@
 <!DOCTYPE html>
 <html><head>
 <meta charset="UTF-8">
-<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.9.0-alpha2/katex.min.css" crossorigin="anonymous">
-<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/default.min.css">
-<script src="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.9.0-alpha2/katex.min.js" crossorigin="anonymous"></script>
-<script src="https://cdnjs.cloudflare.com/ajax/libs/KaTeX/0.9.0-alpha2/contrib/auto-render.min.js" crossorigin="anonymous"></script>
-<script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/highlight.min.js"></script>
-<script src="https://unpkg.com/mermaid@7.1.2/dist/mermaid.min.js"></script>
 <style>
 @charset "utf-8";
 
