Add missing mixins to Forge

Add issues url to the mod
Add water hunting to avians

minecraftforge/src/main/resources/META-INF/mods.toml

@@ -1,8 +1,15 @@
 modLoader = "javafml" #mandatory
 loaderVersion = "${minecraftforge_version_range}" #mandatory This is typically bumped every Minecraft version by Forge. See https://files.minecraftforge.net/ for a list of versions.
 license = "${license}" # Review your options at https://choosealicense.com/.
-#issueTrackerURL="https://change.me.to.your.issue.tracker.example.invalid/" #optional
+issueTrackerURL = "${issue_url}" #optional
 #clientSideOnly=true #optional
+
+[[mixins]]
+config = "${mod_id}.mixins.json"
+
+[[mixins]]
+config = "${mod_id}.minecraftforge.mixins.json"
+
 [[mods]] #mandatory
 modId = "${mod_id}" #mandatory
 version = "${version}" #mandatory