Remove extra space from package.exports default entry

[phil-mellor]

Hi there. This is my first PR contribution on GitHub so please bear with me if I'm doing something wrong!

This PR fixes the error [commonjs--resolver] Failed to resolve entry for package ".....". The package may have incorrect main/module/exports specified in its package.json: No known conditions for "." specifier in "....." package when importing from the addon package.

There's a leading space in exports/./ default that needs removing.

Currently the addon's package.json looks like this:

"exports": {
    ".": {
      "types": "./declarations/index.d.ts",
      " default": "./dist/index.js"
    },
    "./addon-main.js": "./addon-main.cjs",
    "./*.css": "./dist/*.css",
    "./*": {
      "types": "./declarations/*.d.ts",
      "default": "./dist/*.js"
    }
  }

[mansona]

I noticed this the other day but didn't get a chance to fix it 😂 thanks for the contribution 🎉