Postfix templates: allow to provide helpId for template editors

java/java-impl/src/com/intellij/codeInsight/template/postfix/templates/editable/JavaPostfixTemplateEditor.java

@@ -133,6 +133,11 @@ public class JavaPostfixTemplateEditor implements PostfixTemplateEditor {
     return myPanel;
   }
 
+  @Override
+  public String getHelpId() {
+    return "reference.custom.postfix.templates";
+  }
+
   private static Document createDocument(@Nullable Project project) {
     if (project == null) {
       return EditorFactory.getInstance().createDocument("");

platform/lang-impl/src/com/intellij/codeInsight/template/postfix/settings/PostfixEditTemplateDialog.java

@@ -62,4 +62,10 @@ public class PostfixEditTemplateDialog extends DialogWrapper {
                       .addComponentFillVertically(myEditor.getComponent(), 0)
                       .getPanel();
   }
+
+  @Nullable
+  @Override
+  protected String getHelpId() {
+    return myEditor.getHelpId();
+  }
 }

platform/lang-impl/src/com/intellij/codeInsight/template/postfix/templates/editable/PostfixTemplateEditor.java

@@ -19,4 +19,8 @@ public interface PostfixTemplateEditor extends Disposable {
 
   @NotNull
   JComponent getComponent();
+
+  default String getHelpId() {
+    return null;
+  }
 }