idevice*, iproxy: add pages (#14363)

Co-authored-by: Juri Dispan <juri.dispan@posteo.net>
Co-authored-by: Wiktor Perskawiec <git@spageektti.cc>
Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>

pages/common/idevicebackup.md

@@ -0,0 +1,13 @@
+# idevicebackup
+
+> Create or restore backups for iOS devices.
+> Note: This tool is outdated. Please see `idevicebackup2`.
+> More information: <https://manned.org/idevicebackup>.
+
+- Create a backup of the device in the specified directory:
+
+`idevicebackup backup {{path/to/directory}}`
+
+- Restore a backup from the specified directory:
+
+`idevicebackup restore {{path/to/directory}}`