Add counter documentation/examples. Tweak counter triggers/actions in automod.

Rename change_counter automod action to add_to_counter,
add set_counter action, rename counter trigger to counter_trigger.

dashboard/src/components/docs/DocsLayout.vue

@@ -115,6 +115,10 @@
           to: '/docs/setup-guides/moderation',
           label: 'Moderation',
         },
+        {
+          to: '/docs/setup-guides/counters',
+          label: 'Counters',
+        },
       ],
     },
   ];