Solving issue #19 feat: improve existing button components

[The-x-35]

I solved the issue #19 . Combined primary and secondary button into a single component and edited their all instances in the code to fit the new use case, also edited the readme for the new button component. I have tested the code and also tested all the instances where the button was being used and they all work perfectly.

[anwarulislam]

The idea was not just to remove ButtonSecondary. Instead, we will be using the same button component, where a prop will differentiate the type of the button.

[The-x-35]

How will I achieve that sir ?
I am confused on how to proceed with that one ?
I commented my approach on the issue that I will remove the secondary button and do this, so I was assigned this issue.