fix(ngrx.io): preserve sidenav width for larger menu items (#3923)

Author: markostanimirovic

projects/ngrx.io/src/styles/1-layouts/_sidenav.scss

@@ -8,6 +8,7 @@
 aio-nav-menu {
   display: block;
   margin: 0 auto;
+  max-width: 268px;
   @include typescale-small;
   ul, a {
     padding: 0;