Document "-u" option for hide command

man/man1/git-secret-hide.1

@@ -27,6 +27,7 @@ It is possible to modify the names of the encrypted files by setting \fBSECRETS_
 \-v  \- verbose, shows extra information\.
 \-c  \- deletes encrypted files before creating new ones\.
 \-d  \- deletes unencrypted files after encryption\.
+\-u  \- updates/adds hash of unecrypted files to path mappings, (encrypts files on change only)\.
 \-h  \- shows help\.
 .
 .fi

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

@@ -17,6 +17,7 @@ It is possible to modify the names of the encrypted files by setting `SECRETS_EX
     -v  - verbose, shows extra information.
     -c  - deletes encrypted files before creating new ones.
     -d  - deletes unencrypted files after encryption.
+    -u  - updates/adds hash of unecrypted files to path mappings (encrypts files only on change).
     -h  - shows help.