Revert "Rewrote to not use .ird, turn's out they're not needed"

This reverts commit f8b35fbe83.

README.md

@@ -9,6 +9,7 @@ extracting, repackaging, and encrypting PS3 ISOs.
 A hackable, crossplatform, alternative to ISOTools and ISO-Rebuilder.
 
 
+
 [see also](http://www.psdevwiki.com/ps3/Bluray_disc#Encryption) ([archive.fo](https://archive.fo/hN1E6)) 
 
 [7bit encoded int / RLE / CLP](https://github.com/Microsoft/referencesource/blob/master/mscorlib/system/io/binaryreader.cs#L582-L600)
@@ -16,8 +17,16 @@ A hackable, crossplatform, alternative to ISOTools and ISO-Rebuilder.
 clp = compressed length prefix
 
 
-## Possibly todo
+## Todo
 
+- Automatically download .ird file if not given
 - Docstrings
 - Extract ISO (currently doable with `7z x output.iso`
+- Test .irds with version < 9
+- Custom command to backup all irds available
+
+## Advanced
+
+Figure out the SCSI commands to get data1, if at all possible.
+