fix(pkg): add main entry point (#662)

* add main entry point so eslint doesn't complain with the unresolved error `Unable to resolve path to module '@octokit/core'`

* add "types"

Author: deniak

scripts/build.mjs

@@ -55,6 +55,8 @@ async function main() {
       {
         ...pkg,
         files: ["dist-*/**", "bin/**"],
+        main: "./dist-src/index.js",
+        types: "./dist-types/index.d.ts",
         exports: {
           ".": {
             types: "./dist-types/index.d.ts",