Complete README.md with project title and copyright footer

Author: 1DeliDolu

README.md

@@ -1,11 +1,16 @@
+# Introduction to Git and GitHub
+
+## Simple Interest Calculator
+
 A calculator that calculates simple interest given principal, annual rate of interest and time period in years.
 
 ```
-
 Input:
    p, principal amount
    t, time period in years
    r, annual rate of interest
-Output
+Output:
    simple interest = p*t*r
 ```
+
+_© 2022 XYZ, Inc._