update help.zon

src/help.zon

@@ -348,6 +348,19 @@
     \\          contribute to computed styles (and therefore to visibility checks like
     \\          display, visibility, opacity, pointer-events).
     \\          Defaults to false, except in agent mode with an LLM, where it is on.
+    \\  --load-resources <LIST>
+    \\          Comma-separated list of sub-resources to actually request.
+    \\          Defaults to empty, i.e. none of them.
+    \\          Allowed values: "image".
+    \\          "image" requests <img> sources so that load/error events reflect the
+    \\          real HTTP status, instead of load firing for any non-empty src. The
+    \\          request stops at the end of the response headers, so only a small
+    \\          image's body is ever transferred, and images are never decoded:
+    \\          naturalWidth/naturalHeight stay 0 either way.
+    \\          Requested images delay the window load event, and therefore
+    \\          --wait-until load. They are fetched at a lower priority than
+    \\          scripts, stylesheets and XHR, and never take a connection one of
+    \\          those is waiting for.
     \\  --http-cache-dir <PATH>
     \\          Directory used as a filesystem cache for network resources. Omitting
     \\          this disables caching.