feat: update ngit command reference

as the ngit api changed from clain to init

src/routes/+page.svelte

@@ -60,9 +60,7 @@
         </div>
         <button
           on:click={() =>
-            alert(
+            alert('install ngit and run `ngit init` your local git repository')}
-              'install ngit and run `ngit claim` your local git repository'
-            )}
           class="btn btn-secondary">list your repository</button
         >
       </div>