feat: update gene references to use string identifiers in kubejs.mdx

Author: aaronhowser1

docs/geneticsresequenced/devs/kubejs.mdx

@@ -12,13 +12,12 @@ I can't remember how to listen to third party events so I'll just leave it like
 
 ```js
 const $GenesData = Java.loadClass('dev.aaronhowser.mods.geneticsresequenced.attachment.GenesData')
-const $GeneRegistry = Java.loadClass('dev.aaronhowser.mods.geneticsresequenced.registry.ModGenes')
 ```
 
 ```js
-$GenesData.addGene(livingEntity, $GeneRegistry.CHATTERBOX)
-$GenesData.removeGene(livingEntity, $GeneRegistry.LAY_EGG)
-let hasSlimyDeath = $GenesData.hasGene(livingEntity, $GeneRegistry.SLIMY_DEATH)
+$GenesData.addGene(livingEntity, "geneticsresequenced:chatterbox")
+$GenesData.removeGene(livingEntity, "geneticsresequenced:lay_egg")
+let hasSlimyDeath = $GenesData.hasGene(livingEntity, "geneticsresequenced:slimy_death")
 ```
 
 This uses reflection to load the [GenesData](https://github.com/Berry-Club/Genetics-Resequenced/blob/NeoForge-1.21/src/main/kotlin/dev/aaronhowser/mods/geneticsresequenced/attachment/GenesData.kt) and [ModGenes](https://github.com/Berry-Club/Genetics-Resequenced/blob/NeoForge-1.21/src/main/kotlin/dev/aaronhowser/mods/geneticsresequenced/registry/ModGenes.kt) classes, allowing you to use their functions.