Update instructions.

[DaveKap]

People may be using this as more than just a backup utility. Personally, I would like to use it as a way to merge my Signal conversation history back in with my default SMS/MMS history.

I feel like the suggestion in another issue thread about using "file" (linux) or "TrID" (windows) should be included with the Wiki instructions so people know what to expect with the output of signal-backup-decode and how to process it.

If the developer has a suggestion for how to merge this data in with SMS/MMS history (for Android, the SMS Backup & Restore app is the most popular) that too should be added to the Wiki.

[tmo1]

You can try my 'sms-db' program - it can import SMS and MMS messages (I'm not sure about Signal end-to-end encrypted messages) from Signal backups, SMS Backup and Restore XML files, and Android Bugle databases, and export the resulting collection in SMS Backup and Restore XML format. MMS export is experimental, but I think SMS export is pretty solid.