Update _index.md

Author: ConnorLand

content/en/docs/releasenotes/mobile/native-template/nt-studio-pro-11-parent/_index.md

@@ -9,6 +9,8 @@ These are the current Native Template versions for Studio Pro 11 in active devel
 
 * Native Template versions of [19](/releasenotes/mobile/nt-19-rn/) are compatible with apps built using the following versions of Studio Pro:
     * Studio Pro 11.10 and above.
+* Native Template versions of [18](/releasenotes/mobile/nt-18-rn/) are compatible with apps built using the following versions of Studio Pro:
+    * Studio Pro 11.9.x.
 * Native Template versions of [17](/releasenotes/mobile/nt-17-rn/) are compatible with apps built using the following versions of Studio Pro:
     * Studio Pro 11.6 and above.
 * Native Template versions of [16](/releasenotes/mobile/nt-16-rn/) are compatible with apps built using the following versions of Studio Pro: