Add adduser to admin view

static/js/admin.js

@@ -27,6 +27,25 @@ Object.defineProperty(String.prototype, 'hashCode', {
 function render_table(data) {
     const users = Object.values(data.users);
 
+    const newusername = document.querySelector("#newusername");
+    const newuserbutton = document.querySelector("#newuserbutton");
+
+    newuserbutton.addEventListener("click", async () => {
+        const r = await fetch(admin_api_path + 'add_user', {
+            method: "POST",
+            body: JSON.stringify({
+                username: newusername.value,
+            }),
+        });
+
+        if (r.status !== 200) {
+            console.log("something went wrong");
+            return;
+        }
+
+        update_table();
+    })
+
     const tbody = document.querySelector("#scoreboard tbody");
 
     while (tbody.children.length) {