Fixed typo in README.md - updated footer to 2023

Author: daniel-allen-mba

README.md

@@ -1,3 +1,4 @@
+2023 XYZ, Inc.
 # Introduction to Git and GitHub
 
 ## Simple Interest Calculator
@@ -13,4 +14,4 @@ Output
    simple interest = p*t*r
 ```
 
-_© 2022 XYZ, Inc._
+_© 2023 XYZ, Inc._