Update How Genrelizer Works.md to reflect standalone status

Author: Frickitickitavi

docs/How Genrelizer Works.md

@@ -1,7 +1,9 @@
 # How Genrelizer Works
 When YARG starts up, it consults Genrelizer's data to create a large dictionary of case-insensitive mappings from strings to `(genre, subgenre)` value pairs (with the subgenre being optional). For example, the dictionary maps `Rock` to `(Rock, null)`, because it's standard genre, and it maps `Hard Trance` to `(Trance, Hard Trance)`, because it understands that `Hard Trance` is a subgenre of `Trance`.
 
-Under the `mappings` directory, you'll find a bunch of JSON files - one for each of YARG's official genres. Each file contains a JSON object that defines string mappings for the dictionary. As a contrived example, let's suppose that we weren't satisfied with just `Polka` as a standalone genre, and we decided to branch off a whole dedicated `Hardcore Polka` genre to separate the men from the boys.
+Under the `mappings` directory, you'll find a bunch of JSON files - one for each of YARG's official genres. Each file contains a JSON object that defines string mappings for the dictionary.
+
+The rest of this document walks through the creation of a hypothetical new mappings file. In the README, we imagined a scenario where we added a dedicated `Polka` genre. Now let's imagine a world where that wasn't specific enough, and we decided to split off a new `Hardcore Polka` genre to separate the men from the boys.
 
 ## Standard Genres
 
@@ -120,4 +122,4 @@ Lastly, there is one more optional property that is unique to the `subgenre` obj
 }
 ```
 
-You do not need to provide an `en-US` value, because the property name implicitly acts as that value. When a localization is not provided for the player's selected language, we fall back to the `en-US` value.
+You do not need to provide an `en-US` value, because the property name implicitly acts as that value. When a localization is not provided for the player's selected language, we fall back to the `en-US` value.