better router, add sharing support

src/components/App.svelte

@@ -1,10 +1,19 @@
 <Router>
-    <Route path="/share/:domain/:statusId" component={Share} />
-    <Route path="/" component={Home} />
+    {#each routes as { duplex, component }}
+        <Route path={duplex.spec} component={component} />
+    {/each}
 </Router>
 
 <script>
     import { Router, Route } from 'svelte-routing'
+    import { home, share } from '/routes.js'
     import Home from '/routes/Home.svelte'
     import Share from '/routes/Share.svelte'
+
+    const pair = (duplex, component) => ({ duplex, component })
+
+    const routes = [
+        pair(share, Share),
+        pair(home, Home)
+    ]
 </script>