Translate two missing sentences in the article 'promise-error-handling' by NitiemaAllassane · Pull Request #580 · javascript-tutorial/fr.javascript.info

This pull request completes the French translation of the article promise-error-handling by translating two missing sentences that were still in English.

Sentence 1:
In the example below the .catch successfully handles the error:
Dans l’exemple ci-dessous, le .catch gère correctement l’erreur.

Sentence 2:
The execution jumps from the first .catch () to the next one (**) down the chain.
L’exécution passe du premier .catch () au suivant (**) plus bas dans la chaîne.

Linked to issue: #510