docs(brand): add a11y documentation (#2778)

packages/v4/src/content/accessibility/brand/brand.md

@@ -0,0 +1,16 @@
+---
+id: Brand
+section: components
+---
+
+A **brand** is used to place a product logotype on a screen.
+
+**Keyboard users** should not be able to focus on the brand, as it is not interactive.
+
+**Screen reader users** should be able to navigate to the brand and have a screen reader read the brand’s descriptive text.
+
+The following props/attributes have been added for you or are customizable in PatternFly:
+
+| React prop | React component it should be applied to | Which HTML element it appears on in markup | Reason used |
+| -- | -- | -- | -- |
+| alt | Brand | `.pf-c-brand` | Descriptive alternative text for the image of the Brand |