allow variable number of checkboxes

main.js

@@ -73,6 +73,16 @@
     return container
   }
 
+  function createFromMulti(rows, classList, data) {
+    let rowData = []
+    let toIndex = data.to ?? rows.length - 1
+    for (let i = data.from; i <= toIndex; i++) {
+      rowData.push({ index: i })
+    }
+
+    return createFrom(rows, classList, rowData)
+  }
+
   function addCss(link) {
     let css = document.createElement("link")
     css.href = link
@@ -856,13 +866,10 @@
 
   /* BOTTOM OPTIONS */
 
-  let bottomOptionsContainer = createFrom(rows, "options bottom-options", [
-    { index: 59 },
-    { index: 60 },
-    { index: 61 },
-    { index: 62 },
-    { index: 63 }
-  ])
+  let bottomOptionsContainer = createFromMulti(rows, "options bottom-options", {
+    from: 59,
+    to: rows.length - 3
+  })
 
   /* APPEND ALL */