add package.json and .npmignore to improve npm workflows; fixes #1328

.npmignore

@@ -0,0 +1,7 @@
+.DS_Store
+docs/build/html-mathjax-site
+config/local/*.js
+!config/local/local.js
+unpacked/config/local/*.js
+!unpacked/config/local/local.js
+fonts/HTML-CSS/TeX/png

package.json

@@ -0,0 +1,24 @@
+{
+  "name": "mathjax",
+  "version": "2.6.0",
+  "description": "Beautiful math in all browsers. MathJax is an open-source JavaScript display engine for LaTeX, MathML, and AsciiMath notation that works in all browsers.",
+  "keywords": [
+    "math",
+    "svg",
+    "MathML",
+    "TeX",
+    "AsciiMath"
+  ],
+  "maintainers": [
+    "MathJax Consortium <info@mathjax.org> (http://www.mathjax.org)"
+  ],
+  "bugs": {
+    "url": "http://github.com/mathjax/MathJax/issues"
+  },
+  "license": "Apache-2.0",
+  "repository": {
+    "type": "git",
+    "url": "git://github.com/mathjax/MathJax.git"
+  },
+  "main": "./MathJax.js"
+}