Add notice for document translation.

docs/en/Contribution/Index.md

@@ -29,6 +29,14 @@ You may want to translate the complete [documentation](https://abp.io/documents/
 * Get the ["en" folder](https://github.com/abpframework/abp/tree/master/docs/en) as a reference for the file names and folder structure. Keep the same naming if you are translating the same documentation.
 * Send a pull request (PR) once you translate any document. Please translate documents & send PRs one by one. Don't wait to finish translations for all documents.
 
+There are some fundamental documents need to be translated before publishing a language on the [ABP documentation web site](https://docs.abp.io):
+
+* Getting Started documents
+* Tutorials
+* CLI
+
+A new language is published after these minimum translations have been completed.
+
 ### Resource Localization
 
 ABP framework has a flexible [localization system](../Localization.md). You can create localized user interfaces for your own application.