Fill out README.md

README.md

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-saturn-patch
-------------
+# saturn-patch
 
 Reversible region and manufacturer patcher for sega saturn games.
 
 Unlike other utilities that do this, this is open source, safe, cross platform, but most importantly, allows you to
-"unpatch" your changed files by storing small backup files.  The sha256 hash of the original file and the backup file are
-stored in the backup so you can be confident your games can be put back to byte-for-byte original whenever you wish.
+"unpatch" your changed files by storing small backup files next to them.  The sha256 hash of the original file and the
+backup file are stored in the backup so you can be confident your games can be put back to byte-for-byte original
+whenever you wish.
 
-Examples
---------
+### How to use
+
+On Windows or some DEs, simply drag saturn bin files onto the saturn-patch executable.  It will only modify saturn files
+with the region header in them and then only if it can successfully unpatch it and after it writes the backup file to
+disk, so you can safely just run it on all your files.
+
+##### Customize Regions
+
+Set the environmental variable `SATURN_REGION` with your desired regions in order from most preferred to least.  If not
+set the default is `JUBLKTEA`, which is Japan, USA, Brazil, Latin America, Taiwan, Europe, Asia.
+
+##### Customize Manufacturer
+
+Set the environmental variable `SATURN_MANUFACTURER` to whatever you wish, as long as it's less than 16 characters.  If not
+set the default is `SEGA TP T-81`.  Why would you want to do this?  So you can [swap disks](https://youtu.be/fp-U-s8Xdo0)
+with a burned KD02 disk the easy way.
+
+#### How do I get it
+
+You can download `saturn-patch` from the releases section, compile it yourself, or run `cargo install saturn-patch`.
+Where is `saturn-unpatch` you ask?  It's the same executable, make a symbolic link to it, or copy and rename.
+
+### Examples
 
 ```sh
+# patch single file
+saturn-patch panzer-dragoon.bin
+
+# unpatch single file
+saturn-unpatch panzer-dragoon.bin
+# unpatch single file by sending in backup file
+saturn-unpatch panzer-dragoon.bin.saturnpatchbak
+
 # patch all bin files recursively in this directory
-find -type f -name '*.bin' -print0 | xargs -0 saturn-patch 2>&1 | tee saturn-patch.log
+find -type f -iname '*.bin' -print0 | xargs -0 saturn-patch
+
 # unpatch all bin files for which we have a .saturnpatchbak file for recursively in this directory
-find -type f -name '*.saturnpatchbak' -print0 | xargs -0 saturn-unpatch 2>&1 | tee saturn-unpatch.log
+find -type f -name '*.saturnpatchbak' -print0 | xargs -0 saturn-unpatch
 ```