Document options

[sindresorhus]

It should be easy to see what options are supported and what they do.

Currently you have to dig into the source to find them:

traceur-compiler/src/Options.js

Lines 26 to 62 in 0c3dad3

	annotations: false,
	arrayComprehension: false,
	arrowFunctions: true,
	asyncFunctions: false,
	blockBinding: true,
	classes: true,
	commentCallback: false,
	computedPropertyNames: true,
	debug: false,
	defaultParameters: true,
	destructuring: true,
	exponentiation: false,
	forOf: true,
	freeVariableChecker: false,
	generatorComprehension: false,
	generators: true,
	memberVariables: false,
	moduleName: false,
	modules: 'register',
	numericLiterals: true,
	outputLanguage: 'es5',
	propertyMethods: true,
	propertyNameShorthand: true,
	referrer: '',
	require: false,
	restParameters: true,
	script: false,
	sourceMaps: false,
	spread: true,
	symbols: false,
	templateLiterals: true,
	typeAssertionModule: null,
	typeAssertions: false,
	types: false,
	unicodeEscapeSequences: true,
	unicodeExpressions: true,
	validate: false,

And the Node interface supports additional options like filename and modules.

[johnjbarton]

https://github.com/google/traceur-compiler/wiki/Options-for-Compiling

The usage message needs to be updated in source.