use song id for links between show category and songs

src/components/show_category.vue

@@ -45,7 +45,7 @@
 				<td>
 					<ul>
 						<li v-for="song in session.songs">
-							<a v-bind:href="'#/songs/' + song.title">
+							<a v-bind:href="'#/songs/' + song.id">
 								{{song.title}}
 							</a>
 						</li>

src/components/songs.vue

@@ -31,7 +31,7 @@
 			<tr v-for="song in songs">
 				<td>{{song.id}}</td>
 				<td>
-					<a v-bind:name="'/songs/' + song.title">
+					<a v-bind:name="'/songs/' + song.id">
 						{{song.title}}
 					</a>
 					<br/>