Improve initial setup process

[anthonyec]

• Build TS to JS so that it can be installed via NPM
• Handle output directory not existing
• Handle .staticbuildrc.js not existing. Auto generate it?
• Handle directories not existing, such as _functions and _data etc
• Handle getPages and getAssets returning undefined or incorrect data

[anthonyec]

Show a basic example in docs?

module.exports = {
  async getPages() {
    return [
      {
        title: 'News',
        url: '/',
        content: 'Hello!',
        outputPath: './dist/index.html'
      }
    ];
  }
};