Specify tsconfig.json file

[sam-s4s]

It doesn't appear that there is any way to specify a custom tsconfig.json path/name.

For example, my project has 2, and the one I want to point this plugin at is called "tsconfig_jit.json".

Would be clean and super handy :)

[notoriousb1t]

I put in a pull request for this in PR #71

[PaulBGD]

Closing issues that I've integrated into #91, will be merged into master soon.