refactor: increase number of default shows in grid-view

This increases the chance of a perfect 3 column layout.

src/Pages/MyShows.vue

@@ -135,7 +135,7 @@ import Pagination from '@/components/generic/Pagination.vue'
 import AddShowButton from '@/components/shows/AddShowButton.vue'
 
 const TABLE_SHOWS_PER_PAGE = 12
-const GRID_SHOWS_PER_PAGE = 10
+const GRID_SHOWS_PER_PAGE = 12
 
 type DisplayMode = 'grid' | 'table'
 type OrderField = 'is_owner' | 'is_active' | 'slug' | 'updatedAt' | 'updatedBy' | 'id'