feat(react): allow markdown in FormLabel description, allow as prop in custom Link component

[karrui]

Problem

Some designs in Figma contains Form label descriptions with links. This seemed easier to achieve in markdown and thus the ability for markdown in FormLabel.Description is implemented.

See

Whilst doing so, realize the Link component cannot be re-morphed into another type using the as prop which is a common in ChakraUI. This commit was cherry picked from commit 22faa66 in #2683.

Solution

Features:

• Add useMarkdown prop in FormLabel.Description and useMarkdownForDescription prop in the main FormLabel component to allow markdown in form label descriptions.
• Allow as prop in custom Link component

Before & After Screenshots

New story added in Storybook for markdown in form label description.