Add ability for passing in a different "tsconfig.json" file

[littlespice33]

I would like to begin by saying that I love this package and that I have a workaround which is manually modifying my tsconfig using jq before and after I compile using ncc

I would like to have an input allowing an override of the default tsconfig.json file if the input is given

Right now we can do something like this:

ncc build ./src/file-that-i-care-about.js -o ./different-spot-dist would use plain old tsconfig.json

However I would like an option of doing something like the following

ncc build ./src/file-that-i-care-about.js -o ./different-spot-dist --config other-tsconfig.json

Is there any reason this would be problematic? Any other questions about this?

[littlespice33]

Looks like it's already in progress: #1197