Support comma segmentation split

[yisibl]

Input:

.foo {
  color: rgba(68,120,10,.5);
  background-image: linear-gradient(to top right,red,white,blue);
}

Output:

.foo {
  color: rgba(68, 120, 10, .5);
  background-image: linear-gradient(to top right, red, white, blue);
}

[ben-eb]

Done https://github.com/ben-eb/perfectionist/commit/02e6c4bfcaec9972b6f4930f975871ae02b7f74e.