Feature/add review pr option

use `./eb --review-pr 1017 -D | less -R` to try this out.
TODO:
 - [ ] Compare with other files found in the same PR
 - [ ] add legend on top
 - [ ] add documentation / docstrings
 - [ ] figure out how to display added/removed spaces



my code snippet enables searching for files in different subdirectories of path, by simply prefixing the specified glob pattern a couple of times

with a regex approach, you would need to use `os.listdir` on each of them, and then filter using the regex on their results, etc., which seems more elaborate

glob patterns are fine here imho, no need to use regex's which are intended for more complicated pattern matching/searching?