Update translation.json for Spanish

[baleriaa]

Changes:
There is the addition of Spanish text that mimics what is stated in the English file. There is also one small grammar correction of previously added text

• npm run lint passes
• [Inline documentation] is included / updated
• [Unit tests] are included / updated

[welcome]

🎉 Thanks for opening this pull request! Please check out our contributing guidelines if you haven't already. And be sure to add yourself to the list of contributors on the readme page!

[Qianqianye]

Thanks @baleriaa!
I'm tagging the Spanish translation stewards to review the updates: @Guirdo, @Andreu-G, @dnd-alv, @holomorfo

Since the translation you did is about FES, I'm tagging the FES contributor/mentors this summer to double check @Ayush23Dash @almchung @nbriz

[holomorfo]

Small change requested on one line, rest looks good. Thank you.

[holomorfo]

The original is "The media that tried to play (with '{{src}}') wasn't allowed to by this browser, most likely due to the browser's autoplay policy.\n\n+ More info: {{url}}"

I suggest "navegador" instead of browser. Also the structure of the first sentence would be better in my opinion as: "Su navegador impidió la reproducción del contenido multimedia (de '{{src}}'.), posiblemente debido a las reglas de autoplay..."

[Qianqianye]

Thanks @holomorfo for the suggestion. @baleriaa, could you adjust the translation based on the suggestion? After that, we can merge this PR. Thank you!

[Ayush23Dash]

I think I missed it somehow, this PR looks good to me. After implementing the suggestion, we can merge it.