Optimize all modals (fetching). Implement add-player modal.

static/index.js

@@ -69,4 +69,24 @@ function getSelectedClan(event) {
     const clanList = document.querySelector(clanListId);
 
     return clanList.options[clanList.selectedIndex];
-}
+}
+
+function loadClans() {
+    const homeClanList = document.getElementById('home-clan');
+    const oppClanList = document.getElementById('opponent-clan');
+
+    fetch('/clans_html')
+        .then(response => {
+            if (!response.ok) {
+                throw new Error('Network response was not ok');
+            }
+            return response.text();
+        })
+        .then(data => {
+            homeClanList.innerHTML = data;
+            oppClanList.innerHTML = data;
+        })
+        .catch(error => {
+            console.error('There has been a problem with your fetch operation:', error);
+        });
+}