Added installation of type definitions and tsd to get project started…

[killianbrackey]

Added missing steps to get the project running! Thanks for the example!

[markogresak]

Npm install runs a postinstall script, which should (re)install tsd dependencies. Although running tsd install won't hurt.
Btw, you can also use local installation from node_modules/.bin/tsd, if you don't want to have tsd installed globally. Scripts inside package.json will do that by default and will shadow global installations where possible.

Note: this project is a bit dated, it was created over a year ago and I did a bad job at keeping with updates, therefore I would recommend to check for updates that were added in the mean time. One that I am sure of is that tsd was deprecated in favor of typings. According to their documentation, it behaves very similar to tsd, but I haven't been using TypeScript for a long time, so I can't say for sure.

Thanks for the contribution @killianbrackey! 👍