Fix side margins on get-involved (#293)

Closes #292

Co-authored-by: Jared He <66887902+jaredjhe@users.noreply.github.com>
Reviewed-on: #293
Reviewed-by: Aditya Thakral <a3thakra@csclub.uwaterloo.ca>
Co-authored-by: j285he <j285he@localhost>
Co-committed-by: j285he <j285he@localhost>

pages/get-involved.module.css

@@ -52,7 +52,7 @@
 
 @media only screen and (max-width: calc(768rem / 16)) {
   .page {
-    margin: calc(30rem / 16);
+    margin: calc(30rem / 16) 0;
   }
 
   .page > header {