chore: fix semantic-release package problem (#47)

Having `react-test-renderer` as a dev dependency in root cause problems
with `react` peer dependencies when releasing. Moved it into `demo` as a
work around.

part of #38

Author: raae

demo/package.json

@@ -11,6 +11,9 @@
     "react": "^17.0.1",
     "react-dom": "^17.0.1"
   },
+  "devDependencies": {
+    "react-test-renderer": "18.2.0"
+  },
   "keywords": [
     "gatsby"
   ],

package.json

@@ -23,7 +23,6 @@
     "identity-obj-proxy": "3.0.0",
     "jest": "29.0.3",
     "prettier": "^2.6.2",
-    "react-test-renderer": "18.2.0",
     "semantic-release": "19.0.5"
   }
 }