add badge for deprecated api endpoints to the template (#126)

src/components/mdx.jsx

@@ -6,6 +6,7 @@ import { Heading } from '@/components/Heading'
 export const a = Link
 export { Button } from '@/components/Button'
 export { CodeGroup, Code as code, Pre as pre } from '@/components/Code'
+export { Badge } from '@/components/Badge'
 
 export const h2 = function H2(props) {
   return <Heading level={2} {...props} />