[skip ci] Add copynotes package.json script

package.json

@@ -24,7 +24,8 @@
     "configdocs": "rm -rf website/docs/config && mkdir website/docs/config && yarn tsx docs/generateConfigDocs.ts",
     "statedocs": "rm -rf website/docs/models && mkdir website/docs/models && yarn tsx docs/generateStateModelDocs.ts",
     "autogen": "yarn statedocs && yarn configdocs && yarn prettier --write website",
-    "releasenotes": "npx prettier --prose-wrap never website/blog/$(ls -Art website/blog/ | tail -n 1)|sed -e '/## Downloads/,+7d'|tail -n +7"
+    "releasenotes": "yarn prettier --prose-wrap never website/blog/$(ls -Art website/blog/ | tail -n 1)|sed -e '/## Downloads/,+7d'|tail -n +7",
+    "copynotes": "yarn --silent releasenotes | xclip -selection clipboard"
   },
   "devDependencies": {
     "@babel/core": "^7.3.4",