Add documentation in CONTRIBUTING.md and npm run help.

Author: rixner

CONTRIBUTING.md

@@ -56,7 +56,52 @@ We try to get to pull requests in a very timely way so they don't languish. Noth
 * pull-request: (on github)
 
 
+### NPM Commands
 
+* `npm run help`
+
+   Help on all `npm` commands.
+
+* `npm run build`
+
+  Production, optimized build.
+
+* `npm run devbuild`
+
+  Development, unoptimized build
+
+* `npm run watch`
+
+  Development, unoptimized build, which will automatically be rebuilt when there are any source changes.
+
+* `npm run dist`
+
+  Prepare the distribution: build the optimized Skulpt, run all tests, build docs.
+
+* `npm run brun <pyfile>`
+
+  Run Python <pyfile> in the browser.  This will automatically rebuild the unoptimized Skulpt first.
+
+* `npm run btest`
+
+  Run the unit tests in the browser.
+
+* `npm run repl`
+
+  Open the REPL.  You need to build Skulpt (either `npm run build` or `npm run devbuild`) first.
+
+* `npm test`
+
+  Run all tests.  You need to build Skulpt (either `npm run build` or `npm run devbuild`) first.
+
+* `npm start <py2|py3> <pyfile>`
+
+  Run pyfile using either Python 2 (py2) or Python 3 (py3).  You need to build Skulpt (either `npm run build` or `npm run devbuild`) first.
+
+* `npm run profile <py2|py3> <pyfile>`
+
+  Run pyfile using either Python 2 (py2) or Python 3 (py3) with the profiler on.  Will report the profiling results to the console.  You need to build the optimized Skulpt (`npm run build`) first.
+  
 
 ## Coding Style and Conventions
 

package.json

@@ -6,6 +6,7 @@
     "skulpt"
   ],
   "scripts": {
+    "help": "node support/build/help.js",
     "regenparser": "node support/build/regenparser.js",
     "prebrun": "npm run devbuild",
     "brun": "node support/run/brun.js -p",

support/build/help.js

@@ -0,0 +1,24 @@
+const chalk = require('chalk');
+
+var commands = {
+    "run help": "Help on all " + chalk.green("npm") + " commands.",
+    "run build": "Production, optimized build.",
+    "run devbuild": "Development, unoptimized build",
+    "run watch": "Development, unoptimized build, which will automatically be rebuilt when there are any source changes.",
+    "run dist": "Prepare the distribution: build the optimized Skulpt, run all tests, build docs.",
+    "run brun <pyfile>": "Run Python <pyfile> in the browser.  This will automatically rebuild the unoptimized Skulpt first.",
+    "run btest": "Run all unit tests in the browser.",
+    "run repl": "Open the REPL. You need to build Skulpt (either " + chalk.green("npm run build") + " or " + chalk.green("npm run devbuild") + ") first.",
+    "test": "Run all tests. You need to build Skulpt (either " + chalk.green("npm run build") + " or " + chalk.green("npm run devbuild") + ") first.",
+    "start <py2|py3> <pyfile>": "Run pyfile using either Python 2 (py2) or Python 3 (py3). You need to build Skulpt (either " + chalk.green("npm run build") + " or " + chalk.green("npm run devbuild") + ") first.",
+    "run profile <py2|py3> <pyfile>": "Run pyfile using either Python 2 (py2) or Python 3 (py3) with the profiler on.  Will report the profiling results to the console. You need to build the optimized Skulpt (" + chalk.green("npm run build") + ") first."
+};
+
+for (command in commands) {
+    console.log(chalk.green("npm " + command));
+    console.log("\t" + commands[command]);
+    console.log("");
+}
+
+
+