Include local version of mathjax

dist/ext/MathJax-3.2.0/composer.json

@@ -0,0 +1,14 @@
+{
+    "name": "mathjax/mathjax",
+    "type": "library",
+    "description": "MathJax is an open-source JavaScript display engine for LaTeX, MathML, and AsciiMath notation that works in all modern browsers.",
+    "keywords": ["math", "js", "LaTeX", "MathML", "AsciiMath"],
+    "homepage": "http://www.mathjax.org/",
+    "license": "Apache-2.0",
+    "authors": [
+        {
+            "name": "MathJax Consortium",
+            "homepage": "https://github.com/mathjax"
+        }
+    ]
+}