docs: create .all-contributorsrc

Author: allcontributors[bot]

.all-contributorsrc

@@ -0,0 +1,23 @@
+{
+  "files": [
+    "README.md"
+  ],
+  "imageSize": 100,
+  "commit": false,
+  "contributors": [
+    {
+      "login": "JesseTG",
+      "name": "Jesse Talavera-Greenberg",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/1175189?v=4",
+      "profile": "https://jesse.tg",
+      "contributions": [
+        "code"
+      ]
+    }
+  ],
+  "contributorsPerLine": 7,
+  "projectName": "fluid-behavior-tree",
+  "projectOwner": "ashblue",
+  "repoType": "github",
+  "repoHost": "https://github.com"
+}