Fix DEP0148 warning message

ERROR  (node:69269) [DEP0148] DeprecationWarning: Use of deprecated folder mapping "./" in the "exports" field module resolution of the package at /Volumes/Dane/Repozytoria/osklad.pl/node_modules/@nuxtjs/sanity/package.json.
Update this package.json to use a subpath pattern like "./*".
(Use `node --trace-deprecation ...` to show where the warning was created)

Node: v16.11.1
NPM: 8.0.0

It is compatible with Node v12 as this state: postcss/postcss#1455 (comment)

package.json

@@ -23,6 +23,7 @@
       "import": "./dist/module.es.js"
     },
     "./": "./",
+    "./*": "./*",
     "./sanity-content": "./dist/components/sanity-content.js",
     "./sanity-file": "./dist/components/sanity-file.js",
     "./sanity-image": "./dist/components/sanity-image.js"