Fix MDX syntax in rich-text field documentation

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

content/docs/fields/rich-text.mdx

@@ -59,11 +59,11 @@ interface RichTextFieldSchema {
 ## Supported Formats
 
 ### Markdown
-- **Headings**: # H1, ## H2, ### H3
-- **Bold/Italic**: **bold**, *italic*
+- **Headings**: `# H1`, `## H2`, `### H3`
+- **Bold/Italic**: `**bold**`, `*italic*`
 - **Lists**: Ordered and unordered
-- **Links**: [text](url)
-- **Images**: ![alt](url)
+- **Links**: `[text](url)`
+- **Images**: `![alt](url)`
 - **Code**: Inline and blocks
 - **Tables**: Markdown tables