_toctree: add vae encode

Author: hlky

docs/source/en/_toctree.yml

@@ -81,6 +81,8 @@
     title: Overview
   - local: hybrid_inference/vae_decode
     title: VAE Decode
+  - local: hybrid_inference/vae_encode
+    title: VAE Encode
   - local: hybrid_inference/api_reference
     title: API Reference
   title: Hybrid Inference