Add funding to package.json

Author: nomcopter

package.json

@@ -13,6 +13,7 @@
     "type": "git",
     "url": "https://github.com/nomcopter/react-mosaic.git"
   },
+  "funding": "https://github.com/nomcopter/react-mosaic?sponsor=1",
   "scripts": {
     "build": "npm-run-all clean -lp build:**",
     "build:ts": "tsc -p tsconfig-build.json",