Add top-level 'types' property in package.json

[khajimatov]

Hey!
I had some issues with types when using astro-selfie, after some research I learned that package.json should contain a top-level types property in order for types to work(link).
Before:

After:

package.json

{
        "name": "astro-selfie",
        ...
+	"types": "./dist/index.d.ts",
	"repository": "vadimdemedes/astro-selfie",
        ...
}