[Proposal] new color for files where nobody depends on (e.g. index.js)

[alaingiller]

Currently there is 3 colors: Blue has dependencies, green has no dependencies, and red has circular dependencies.

It would be great to add a 4th one for "start" file like index.ts for example. Usually it should have only one such file, but there is case where there is more than one and it currently difficult to see such files

[PabloLION]

Maybe use other style like bolder boarder for the "start" file? Seems this can be resolved together with

• https://github.com/pahen/madge/issues/249