request: something like `--watch` mode

[dylang]

It would be helpful if there was something like --watch mode, or documentation for how to do this.

Example workflow:

1. We run analyze-trace ts-trace
2. Oh look, a hot spot!

Analyzed /Users/dylang/project/packages/example/tsconfig.json (trace.65458-188.json)
Hot Spots
└─ Check file /Users/dylang/project/packages/example/slow-type-in-here.js (1739ms)
   └─ Check variable declaration from (line 57, char 7) to (line 62, char 2) (1441ms)
      └─ Check expression from (line 57, char 30) to (line 62, char 2) (1441ms)
         └─ Check expression from (line 57, char 30) to (line 57, char 52) (1438ms)
            └─ Compare types 13361 and 4729 (1249ms)

3. We make a change to try to fix it, and hit save....

This is where this feature request starts.

4. analyze-trace automatically runs again. Fewer files may need to be recompiled so analyze-trace is only showing results from those re-compiles. Feature Request
5. The output from analyze-trace tells us how much faster or slower each change is compared to the previous run. Bonus Feature Request