Adding question mark in 'which categories should be available' (#1428)

Author: MMwandigha

apps/web-mzima-client/src/assets/locales/en.json

@@ -1135,7 +1135,7 @@
     "delete_category_desc": "<strong>If you delete this category</strong>, it will no longer be associated with any posts. Proceed with caution.",
     "show_categories": "Show available categories",
     "child_permissions": "Permissions for this category are managed by the parent category.",
-    "which_categories": "Which categories should be available",
+    "which_categories": "Which categories should be available?",
     "select_all": "Select All",
     "choose_roles": "Choose Roles",
     "create_tag": "Create Category",