Add human friendly error codes

src/pages/Signin.js

@@ -49,7 +49,17 @@ export function Signin( props ) {
     })
     .catch( (code) => {
       //console.log(code)
-      setErrorCode( code )
+      // setErrorCode( code )
+      switch(code) {
+        case"auth/invalid-email":
+          setErrorCode("The email address is invalid")
+          break
+        case"auth/invalid-login-credentials":
+        setErrorCode("Credentials supplied is not in our system")
+        break
+        default: 
+        break
+      }
     })
   }