refactor: global declaration

[mauriciord]

• changed global declaration
• removed some redudant variable declarations like const w = window just to return boolean

[Joozty]

Hi @mauriciord 👋,

thanks for your contribution. Is there any reason for making these changes? We use const w = window as SmartlookWindow intentionally so it stays encapsulated. Your change will automatically attach smartlook to the window object and anyone with this package installed can access window.smartlook without their compiler complaining. Obviously, it is correct because window.smartlook exists but the typing is dangerous since it is any. We could maybe make a better interface but for the time being it was done that way. 🙂