Improve join/leave, publish messages

src/app/components/GroupComposeTopic.svelte

@@ -1,10 +1,15 @@
 <script lang="ts">
+  import cx from 'classnames'
   import type {NodeViewProps} from '@tiptap/core'
   import {NodeViewWrapper} from 'svelte-tiptap'
+  import Link from '@lib/components/Link.svelte'
 
   export let node: NodeViewProps['node']
+  export let selected: NodeViewProps['selected']
 </script>
 
-<NodeViewWrapper class="inline text-primary">
-  #<span class="underline">{node.attrs.name}</span>
+<NodeViewWrapper class="inline">
+  <Link external href="https://coracle.social/topics/{node.attrs.name.toLowerCase()}" class={cx("link-content", {'link-content-selected': selected})}>
+    #{node.attrs.name}
+  </Link>
 </NodeViewWrapper>