Add Typescript typings for generators

[samelhusseini]

Is your feature request related to a problem? Please describe.

Include Typescript definitions for Blockly generators.

Describe the solution you'd like

scan the generator directory as part of the typescript definition generation:
https://github.com/google/blockly/tree/master/generators

Feature requested on forums:
https://groups.google.com/forum/#!topic/blockly/Su046eekUZY

[aabounegm]

Any updates on this? I wrote the following workaround in my project:

declare module 'blockly/javascript' {
    import { Generator } from 'blockly';
    const instance: Generator;
    export = instance;
}

but that still doesn't give it the additional properties defined on the Blockly.JavaScript object (which I also can't use because typescript screams that Property 'Javascript' does not exist on type 'typeof Blockly')

[cpcallen]

This was fixed by all the work done to convert the generators to TypeScript (see issue #6828).