Improve accessibility on terminal output

[tinganho]

The output on tsc is not so accessible. I find it hard to read because everything is white and no newlines between lines.

Also when running tsc -w it is very hard to distinguish latest build from the second latest.

These problem can be solved if the output where a little bit more colorized.

[danquirk]

I think @DanielRosenwasser might actually already be working on exactly some things to help out with this.

[tinganho]

ok nice!

[Gaelan]

👍

[myitcv]

Can I ask that if colourisation of terminal output is considered that it be off by default? Covers the case where tools consume the output of tsc.

[DanielRosenwasser]

I've put out #5140 if you guys'd like to try it out and give some feedback. 😃

[DanielRosenwasser]

Give it a try, it should be out in tonight's nightly, and uses the --pretty flag.