docs(angular): add containers content (#6451)

src/data/roadmaps/angular/content/containers@0s-QhN5aZh2F3tLJFKEyR.md

@@ -1 +1,7 @@
-# Containers
+# Containers
+
+Some Angular Material UI components cannot take children, such as an input, so you need to use container elements to customize the UI component.  
+
+Visit the following resources to learn more:
+
+- [@official@Using containers for native elements](https://angular.dev/best-practices/a11y#using-containers-for-native-elements)