webpack et al need to be in main dependencies

[jedwards1211]

Because html-webpack-plugin and so forth are in this package's devDependencies, they're not installed when I add this package as a dep of my project.

$ yarn add --dev module-docs
andy@Andys-MBP-2:clarity (master) $ module-docs start
module.js:549
    throw err;
    ^

Error: Cannot find module 'html-webpack-plugin'
    at Function.Module._resolveFilename (module.js:547:15)
    at Function.Module._load (module.js:474:25)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (/Users/andy/clarity/node_modules/module-docs/lib/webpack.config.js:5:27)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)

[ramsaylanier]

@jedwards1211 thanks for bringing this to my attention - what an oversight!