Provide instructions for usage with babel

[heygrady]

There are issues with how the random number generator code is implemented. It fails with default settings in browserify and babel. (See #172)

There are a number of issue that describe the problem but none that detail the solution.

• There should be notes in the main readme for usage with popular packaging setups, like babel.
• The code should be patched so that it doesn't break by default.

The offending line is relying on global being defined as window. For some reason global === undefined when this library is included in another project and compiled using babel/webpack.

[dessant]

I can second this, after commenting out that line, my webpack bundle does not throw this error anymore:

TypeError: modules[moduleId] is undefined[Learn More]  manifest.bundle.js:55:12

Defining global is also a workaround: webpack/webpack#1887 (comment)