Update docs/topics/mta-web-creating-custom-migration-targets.adoc

Author: mpershina

docs/topics/mta-web-creating-custom-migration-targets.adoc

@@ -20,6 +20,8 @@ By using ready-made custom migration targets, you can avoid configuring custom r
 . Click *Create new*.
 . Enter the name and description of the target.
 . Click the *Provider* drop-down menu and choose the language provider.
++
+IMPORTANT: Support for the Python and Node.js language providers is available as a Technology Preview only.
 . In the *Image* section, upload an image file for the target's icon. The file can be in either the PNG or JPEG format, up to 1 MB. If you do not upload any file, a default icon is used.
 . In the *Custom rules* section, select either *Upload manually* or *Retrieve from a repository*:
 ** If you selected *Upload manually*, upload or drag and drop the required rule files from your local drive.