ContainsAllStrings checks if a haystack contains all needles.

ContainsAnyString checks if a haystack contains any needle.

FilterByDirectory removes all files from a slice that are not in a given directory.

FilterByType removes all files from a list that do not have the suffix ofType The ofType argument should include the dot ".txt", ".go" ...

RelativePathFromTo returns the relative path from directory `from` to the file `to`.