Issue #1592 Improve reporter documentation for mocha in browser.

You can pass the constructor function of your custom reporter in options and mocha will use it.

docs/index.md

@@ -1576,13 +1576,21 @@ mocha.setup({
 
 ### Browser-specific Option(s)
 
-The following option(s) _only_ function in a browser context:
+Browser Mocha supports many, but not all [cli options](#command-line-usage).  
+To use a [cli option](#command-line-usage) that contains a "-", please convert the option to camel-case, (eg. `check-leaks` to `checkLeaks`).
+
+#### Options that have additional/slightly different usage than the corresponding [cli option](#command-line-usage) are listed here:
+
+`reporter` _{string|constructor}_  
+Accepts a reporter name _{string}_ or constructor _{function}_. You can find **recommended** reporters for the browser [here](#reporting). It is possible to use [built-in reporters](#reporters) as well, but we don't recommend it, (you can put your cat in the microwave, but don't blame us).
+
+#### The following option(s) _only_ function in a browser context:
 
 `noHighlighting`: If set to `true`, do not attempt to use syntax highlighting on output test code.
 
 ### Reporting
 
-The "HTML" reporter is what you see when running Mocha in the browser. It looks like this:
+The "html" reporter is the default reporter when running Mocha in the browser. It looks like this:
 
 ![HTML test reporter](images/reporter-html.png?withoutEnlargement&resize=920,9999){:class="screenshot" lazyload="on"}
 

lib/mocha.js

@@ -83,7 +83,7 @@ exports.Test = require('./test');
  * @param {boolean} [options.inlineDiffs] - Display inline diffs?
  * @param {boolean} [options.invert] - Invert test filter matches?
  * @param {boolean} [options.noHighlighting] - Disable syntax highlighting?
- * @param {string} [options.reporter] - Reporter name.
+ * @param {string|constructor} [options.reporter] - Reporter name or constructor.
  * @param {Object} [options.reporterOption] - Reporter settings object.
  * @param {number} [options.retries] - Number of times to retry failed tests.
  * @param {number} [options.slow] - Slow threshold value.