chore(ProConnectButton): fix typo (#298)

Signed-off-by: Julien Bouquillon <julien.bouquillon@beta.gouv.fr>

Author: revolunet

stories/ProConnectButton.stories.tsx

@@ -6,7 +6,7 @@ const { meta, getStory } = getStoryFactory({
     sectionName,
     "wrappedComponent": { ProConnectButton },
     "description": `
-- [See DSFR documentation]https://github.com/numerique-gouv/agentconnect-documentation/blob/main/doc_fs/bouton_proconnect.md)
+- [See DSFR documentation](https://github.com/numerique-gouv/agentconnect-documentation/blob/main/doc_fs/bouton_proconnect.md)
 - [See source code](https://github.com/codegouvfr/react-dsfr/blob/main/src/ProConnectButton.tsx)`
 });