Add Poseidon

Author: tastybento

config.json

@@ -1,5 +1,15 @@
 {
   "addons": [
+    {
+      "name": "Poseidon",
+      "gamemode": true,
+      "github": "BentoBoxWorld/podeidon",
+      "ci": "BentoBoxWorld/Poseidon",
+      "description": "**Poseidon** Welcome to Poseidon, an underwater adventure where\n\the ocean is both your playground and your challenge..\n\nCreated and maintained by tastybento.",
+      "versions": {
+        "1.21.4": "1.0.0"
+      }
+    },
     {
       "name": "Parkour",
       "gamemode": true,