fix(mon-pix): use a max width on global container

Author: Libouk

Diff for: mon-pix/app/styles/globals/_layout.scss

@@ -68,6 +68,7 @@ img {
   width: 100%;
   margin-inline: auto;
   padding-inline: var(--pix-spacing-4x);
+  max-width: 80rem;
 
   @include breakpoints.device-is('desktop') {
     padding-inline: var(--pix-spacing-6x);