git secret hide docs warns about `-F` but not `-m` behaviour #467 (#468)

man/man1/git-secret-hide.1.ronn

@@ -26,8 +26,10 @@ it's possible to make it so some files can no longer be decrypted by users who s
 (and would appear) able to decrypt them, and vice-versa.
 
 If you know what you are doing and wish to encrypt or re-encrypt only a subset of the files 
-even after reading the above paragraphs, you can use the -F option to force `git secret hide` 
-to skip any hidden files where the unencrypted versions aren't present. 
+even after reading the above paragraphs, you can use the -F or -m option to only encrypted 
+a subset of files. The -F option forces `git secret hide` to skip any hidden files 
+where the unencrypted versions aren't present. The -m option skips any hidden files that have 
+not be modified since the last time they were encrypted. 
 
 Also, it is possible to modify the names of the encrypted files by setting `SECRETS_EXTENSION` variable.