docs: add non-interactive icon and search guidance to contained list

src/pages/components/contained-list/style.mdx

@@ -103,14 +103,19 @@ in a phrase and any proper nouns capitalized.
 
 ## Structure
 
-| Element                     | Property                    | px / rem | Spacing token |
-| --------------------------- | --------------------------- | -------- | ------------- |
-| List header area: on-page   | height                      | 32 / 2   | `$spacing-07` |
-|                             | padding-left, padding-right | 16 / 1   | `$spacing-05` |
-| List header area: disclosed | height                      | 48 / 3   | `$spacing-09` |
-|                             | padding-left, padding-right | 16 / 1   | `$spacing-05` |
-| List item                   | padding-left, padding-right | 16 / 1   | `$spacing-05` |
-| Icon (optional)             | height, width               | 16 / 1   | —             |
+| Element                         | Property                    | px / rem | Spacing token |
+| ------------------------------- | --------------------------- | -------- | ------------- |
+| List header area: on-page       | height                      | 32 / 2   | `$spacing-07` |
+|                                 | padding-left, padding-right | 16 / 1   | `$spacing-05` |
+| List header area: disclosed     | height                      | 48 / 3   | `$spacing-09` |
+|                                 | padding-left, padding-right | 16 / 1   | `$spacing-05` |
+| List item                       | padding-left, padding-right | 16 / 1   | `$spacing-05` |
+| Non-interactive icon (optional) | height, width               | 16px     | —             |
+|                                 | padding left, padding-right | 16 / 1   | `$spacing-05` |
+| Inline action icon (optional)   | height, width               | 16px     | —             |
+|                                 | padding left, padding-right | 16 / 1   | `$spacing-05` |
+| Search icon (optional)          | height, width               | 16px     | —             |
+|                                 | padding left, padding-right | 16 / 1   | `$spacing-05` |
 
 <div className="image--fixed">
 
@@ -171,6 +176,30 @@ in a phrase and any proper nouns capitalized.
   Structure and spacing measurements for inline actions. | px / rem
 </Caption>
 
+<br />
+
+<div className="image--fixed">
+
+![Structure and spacing measurements for non-interactive icons.](images/contained-list-decorative-icons-style.png)
+
+</div>
+
+<Caption>
+  Structure and spacing measurements for non-interactive icons. | px / rem
+</Caption>
+
+<br />
+
+<div className="image--fixed">
+
+![Structure and spacing measurements for search and filtering.](images/contained-list-search-style.png)
+
+</div>
+
+<Caption>
+  Structure and spacing measurements for search and filtering. | px / rem
+</Caption>
+
 ## Size
 
 ### On-page list

src/pages/components/contained-list/usage.mdx

@@ -124,10 +124,15 @@ and optional interactive elements.
 </Row>
 
 1. **List header area:** Area to group the succeeding list items.
-2. **List title:** Descriptive name for the group of list items.
-3. **List item:** The content with in a list item row.
-4. **Interactive element** (optional): An interactive element in the header or
-   row such as a button, link, icon, or toggle.
+2. **List item area:** Area to group text and elements in a list row.
+3. **List title:** Descriptive name for the group of list items.
+4. **List item:** The content in a list item row.
+5. **Non-interactive icon (optional):** A decorative icon to help visually
+   describe a list item.
+6. **Search icon (optional):** An icon to represent search or filtering
+   functionality in the contained list.
+7. **Interactive element (optional):** An interactive element in the header or
+   row such as a button, link, icon, tag, or toggle.
 
 ### Alignment
 
@@ -334,6 +339,22 @@ multiple column headers, we recommend using a data table instead.
 </Column>
 </Row>
 
+### Non-interactive icons
+
+Contained lists can have non-interactive icons positioned before the text in
+each row to help visually describe the list item, category, or status. These
+icons are decorative elements and are used for visual purposes only. Icons
+should typically be the same color as the text in the row unless they are status
+indicators.
+
+<Row>
+<Column colLg={8}>
+
+![Contained list non-interactive icons](images/contained-list-non-interactive-icons-usage.png)
+
+</Column>
+</Row>
+
 ### Search and filtering
 
 Contained lists can include a search or filter functionality. The search or