Fix incorrect method definition in Car struct

[chiranjeet-baruah]

This pull request refactors the DisplayInfo method in the Car struct to use a receiver, improving clarity and adhering to Go's conventions for defining methods on structs.

Changes to method definition:

• The DisplayInfo method was moved from being defined inside the Car struct to being defined as a method with Car as the receiver. This change ensures the method operates on a specific instance of Car and accesses its fields using the receiver variable c.