Adding Linux to note

PR for eclipse-archived/codewind#2197

Author: sishida

docs/_documentations/mdt-intellij-getting-started.md

@@ -27,7 +27,7 @@ Complete the prerequisites and choose to install Codewind on IntelliJ with eithe
 3. From the menu, click the **Manage Plugin Repositories...** gear icon.
 4. Click the **+** button.
 5. Enter `https://download.eclipse.org/codewind/milestone/0.9.0/updatePlugins.xml`.
-6. **For IntelliJ on Windows:** After you paste the URL, click outside the entry field so that the URL is deselected. If the URL isn't deselected before clicking **OK**, the URL is saved as a blank entry, and an error occurs.
+6. **For IntelliJ on Linux and Windows:** After you paste the URL, click outside the entry field so that the URL is deselected. If the URL isn't deselected before clicking **OK**, the URL is saved as a blank entry, and an error occurs.
 7. Click **OK**.
 8. Click the **Marketplace** heading.
 9. In the search field, type `codewind`. The `codewind-intellij` plug-in appears. Click **Install**.