Run ./file-statistics.sh <path-to-skywater-src-nda>

all-files: contains all extensions and filenames without extensions
files-with-extensions: contains only extensions, without extensionless filenames
exts-from-spreadsheet: extensions mentioned in the original spreadsheet
missing_exts: extensions not mentioned in exts-from-spreadsheet
missing_exts_with_names: helper file for listing filenames of rare extensions