Clarify wuffsfmt ignores . in paths not contents
//
// Without explicit paths, it rewrites the standard input to standard output.
// Otherwise, the -l or -w or both flags must be given. Given a file path, it
-// operates on that file; given a directory path, it operates on all .wuffs
-// files in that directory, recursively. Files starting with a period are
+// operates on that file; given a directory path, it operates on all *.wuffs
+// files in that directory, recursively. File paths starting with a period are
// ignored.
package main
