UPDATE REQUEST: add custom rules to F function to ignore some dirs by default

[AleixMT]

make F function ignore dirs such as "target" directory, which contains compiled code in java project, ignore .min files, ignore binary files.

We can add new parameters for selection or we can create a new Function to do so, but it does not need to be much different than the F function.

[AleixMT]

We will do a rework of these functions. f will return a list of files and F will look for content into those files. They will work together. And the f function could have a filter or something to avoid certain folders such as target/ folder, where usually we have the compiled code.