docs(design): document article encapsulation

libs/design/article/README.md

@@ -4,41 +4,47 @@ Article provides styles to common element selectors to create an article in a co
 ## Overview
 Article can be used on any content page that displays large blocks of text-driven information. It's meant to be used as a standalone element and should not be nested inside any other components that may change the background color from the anticipated one. In the event that you must nest an article inside another component, please ensure that you set the article's background color to the default body color.
 
-## Headings
+## Supported Elements
+
+### Headings
 <design-land-example-viewer-container example="article-headings"></design-land-example-viewer-container>
 
-## Article Meta
+### Article Meta
 Meta is used if there is metadata information about your article (i.e. author name, date, etc). Meta is a custom directive of article and is not a native element selector. To use it, add `daffArticleMeta` to a paragraph (`<p>`).
 
 <design-land-example-viewer-container example="article-meta"></design-land-example-viewer-container>
 
-## Link
+### Link
 The link style in an article uses the default browser link style.
 
 <design-land-example-viewer-container example="article-link"></design-land-example-viewer-container>
 
-<h2>Table</h2>
+### Table
 <design-land-example-viewer-container example="article-table"></design-land-example-viewer-container>
 
-## Lists
+### Lists
 
-### Unordered List
+#### Unordered List
 <design-land-example-viewer-container example="article-ul"></design-land-example-viewer-container>
 
-### Ordered List
+#### Ordered List
 <design-land-example-viewer-container example="article-ol"></design-land-example-viewer-container>
 
-## Code
+### Code
 These are styles for inline and multiline blocks of code.
 
-### Inline code
+#### Inline code
 <design-land-example-viewer-container example="article-code-inline"></design-land-example-viewer-container>
 
-### Code blocks
+#### Code blocks
 <design-land-example-viewer-container example="article-code-block"></design-land-example-viewer-container>
 
-## Horizontal Rules
+### Horizontal Rules
 <design-land-example-viewer-container example="article-hr"></design-land-example-viewer-container>
 
-## Blockquote
-<design-land-example-viewer-container example="article-blockquote"></design-land-example-viewer-container>
+### Blockquote
+<design-land-example-viewer-container example="article-blockquote"></design-land-example-viewer-container>
+
+## Encapsulation
+
+Articles also support other custom "non-native" components like [Accordions](../accordion/README.md), [Media Galleries](../media-gallery/README.md), and [Lists](../list/README.md). Unlike typical HTML (<p>, <ol>, <ul>, etc) content, these components must be style encaspulated to prevent article styles bleeding down from the article into their content. Many Daffodil components support this out of the box. If you have a custom component that you would like to place inside an article, you can use the `DaffArticleEncapsulatedDirective` on your component to prevent article styles bleeding into your component.