EthicalAd: specific placement for Antora

Based on #473

Author: humitos

src/ethicalads.js

@@ -147,6 +147,17 @@ export class EthicalAdsAddon extends AddonBase {
           placement.classList.add("ethical-alabaster");
           placement.classList.add("ethical-docsify");
 
+          placement.setAttribute("data-ea-type", "readthedocs-sidebar");
+          placement.setAttribute("data-ea-style", "image");
+          knownPlacementFound = true;
+        }
+      } else if (docTool.isAntora()) {
+        selector = "aside nav.nav-menu";
+        element = document.querySelector(selector);
+
+        if (this.elementAboveTheFold(element)) {
+          placement.classList.add("ethical-alabaster");
+
           placement.setAttribute("data-ea-type", "readthedocs-sidebar");
           placement.setAttribute("data-ea-style", "image");
           knownPlacementFound = true;