add lilToon 2.3.1

vpm.json

@@ -6,6 +6,24 @@
   "packages": {
     "jp.lilxyzw.liltoon": {
       "versions": {
+        "2.3.1": {
+          "name": "jp.lilxyzw.liltoon",
+          "version": "2.3.1",
+          "displayName": "lilToon",
+          "description": "Feature-rich toon shader.",
+          "unity": "2022.3",
+          "documentationUrl": "https://lilxyzw.github.io/lilToon/",
+          "changelogUrl": "https://lilxyzw.github.io/lilToon/#/en-us/other/changelog",
+          "licensesUrl": "https://github.com/lilxyzw/lilToon/blob/master/Assets/lilToon/LICENSE",
+          "license": "MIT",
+          "keywords": ["Toon", "Shader", "Material"],
+          "url": "https://github.com/lilxyzw/lilToon/releases/download/2.3.1/jp.lilxyzw.liltoon-2.3.1.zip?",
+          "repo": "https://lilxyzw.github.io/vpm-repos/vpm.json",
+          "legacyFolders": {
+            "Assets\\lilToon": "05d1d116436047941ad97d1b9064ee05"
+          },
+          "zipSHA256": "8fe3df2bfbfc2697db7d6e0c27b6dd421938123331e0c282e6bde946020b35e6"
+        },
         "2.3.0": {
           "name": "jp.lilxyzw.liltoon",
           "version": "2.3.0",