Add CSS dumping guide

faq/dump-css.md

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+## What is CSS?
+
+Before diving in to how best to dump a CSS protected disc in Aaru, you should first have a decent understand of what CSS even is. Basically, it's a standardized and widely used form of encryption for movie DVDs designed to prevent unlicensed players from playing the DVDs, as well as to prevent copies being made of the discs. Sectors encrypted by CSS are marked as such, and the disc and drive have to authenticate one another before playback can start. Not every DVD player can play ever CSS encrypted disc either, as one aspect of CSS encryption is region locking. Basically this means that if the disc is only licensed to play in a certain region, the authentication process will fail if the drive reading it isn't set to that region. Most PC drives do allow you to change which region they're able to read a set number of times, but most standalone DVD players do not. This is purely a form of copy protection, and not a physical or digital difference in encoding, unlike other technologies (such as VHS) that were physically unable to play media from other regions. Every encrypted sector can be decrypted with a so-called title key, and the vast majority of the time, this title key will be the same for every sector on the disc. 
+
+
+
+## Dumping CSS protected discs with Aaru
+
+Now that you know the basics, you're ready to start the dumping process! The first step is to have a compatible DVD/Blu-ray drive installed and ready for Aaru to use. This includes making sure it's authenticated for the region you intend to dump, as Aaru does NOT bypass the region authentication. Next, you have to consider what options you want to use, the most important being ```--store-encrypted``` and ```--title-keys```. When ```--title-keys``` is enabled, Aaru will then bruteforce the title keys on a per sector basis. While other software only does this to obtain a title key once (which does produce functional decrypted images every or almost every time), Aaru does this for every sector for the sake of complete preservation. So while this is needed for Aaru in order to produce a decrypted copy of the disc, it takes a very long time. As in at least overnight long, and quite possibly a fair bit longer, especially for dual layer DVDs. However, if you want to dump the disc with ```--store-encrypted``` enabled, it will store an image with the CSS encryption intact, which means that ```--title-keys``` can safely be disabled. An encrypted image can be easily decrypted with other software (assuming it's converted to a commonly supported format such as ISO), so if you want to make a quick dump that's not 100% geared towards preservation, this is the way to go. With the title keys, it is possible to decrypt and encrypt the disc image at will, but Aaru does not current have this functionality. It is planned to be added in a future update.

quickstart.md

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 ## Extracting files from NTFS/HFS/HFS+/etc. filesystems
 
 Unfortunately, Aaru does not support extracting from several well known filesystems at the moment, some notable ones include NTFS, HFS, and HFS+. In cases like these, if you have an Aaru Format Image, you have to convert it to a more well known image format and use other software to mount and/or navigate it. 
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+
+
+## Dumping a CSS protected DVD-Video
+
+Due to the complexity of this topic, it's in a separate article [here](faq/dump-css.md).