gpg-zip: add page (#2392)

pages/common/gpg-zip.md

@@ -0,0 +1,15 @@
+# gpg-zip
+
+> Encrypt files and directories in an archive using GPG.
+
+- Encrypt a directory into archive.gpg using a passphrase:
+
+`gpg-zip --symmetric --output {{archive.gpg}} {{path/to/directory}}`
+
+- Decrypt archive.gpg into a directory of the same name:
+
+`gpg-zip --decrypt {{path/to/archive.gpg}}`
+
+- List the contents of the encrypted archive.gpg:
+
+`gpg-zip --list-archive {{path/to/archive.gpg}}`