TypeScript support

The AsyncAPI generator has TypeScript support for hooks and Nunjucks's filters. Assumptions:

• Installing the typescript package and creating the tsconfig.json file isn't necessary.
• Source code of the hook/filter must have .ts extension.
• Each package related to the typings for TypeScript like @types/node must be installed in the template under dependencies array. This is because the Generator transpiles the TypeScript code on-the-fly while rendering the template, and cannot use packages under devDependencies.
• Each template should have @types/node package installed to enable support for typings for Node.