Add new option to list folders only, cleaned up other code and documentation

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changed 'Include hidden files in output?' option to only pertain to files. If you want to search for hidden folders you need to add that to the folder filter.
file filter (pattern) defaults to .
added code to deal with all pattterns in file filter when 'Include hidden files in output?' is set
folder filter defaults to *
folder filter will accept '/' and convert them to commas before sending to readdirp
both file filter and folder filter are converted to arrays to be passes to readdirp
added option to return folder anmes only

TotallyInformation / node-red-contrib-fs