typo error in README.md file

[Syed25794]

Previous sentence in local development 8th sentence :
Your Parse Server is "not" running and is connected to your local database named dev in which the data is stored that you manage via Parse Server.

Now correct sentence:
Your Parse Server is "now" running and is connected to your local database named dev in which the data is stored that you manage via Parse Server.

[parse-github-assistant]

Thanks for opening this issue!