Update README.md

Signed-off-by: Glenn Fiedler <glenn@networknext.com>

Author: gafferongames

README.md

@@ -20,7 +20,7 @@ reliable is stable and production ready.
 
 Reliable is designed to operate with your own network socket library.
 
-If you don't have one already, try [netcode](https://github.com/mas-bandwidth/netcode), it was designed to work well with reliable.
+If you don't have one already, try [netcode](https://github.com/mas-bandwidth/netcode), it's designed to work well with reliable.
 
 First, create an endpoint on each side of the connection: