fix: Readme update

[fabriziodemaria]

• Minor fixes
• Remove withContext and add note about using a single instance
• Expand on the Initialization Strategy

[nicklasl]

I wonder if it would make sense to have the user select an initialization strategy as part of the "sdk create function" and having the create function be suspend/async and perform the action right away?

[fabriziodemaria]

I wonder if it would make sense to have the user select an initialization strategy as part of the "sdk create function" and having the create function be suspend/async and perform the action right away?

Yes, I think I would like that. I am especially not a fan of users having to call two functions activate and asyncFetch in succession, I'd rather manage those internally.