Added Spanish translation for tutorial part 12

[salgadev]

Hi. Mexican engineer based in Canada here.
I jumped ahead to tutorial number 12 to avoid conflicts with other Spanish speaking contributors.
Please review and advise.
Thanks

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[nph4rd]

Hey - this looks good. @ricardopretelt and I decided he would do the odd numbers and I would do the even numbers so if you want to keep contributing maybe we can have a quick chat on Slack to reassign the tutorials evenly between us! :) Saludos!

[salgadev]

Hey - this looks good. @ricardopretelt and I decided he would do the odd numbers and I would do the even numbers so if you want to keep contributing maybe we can have a quick chat on Slack to reassign the tutorials evenly between us! :) Saludos!

Hola guys, thanks for replying

Sorry if I didn't follow the workflow, it's my first time contributing.
I'd love to join the Slack and do more work.
Also, I just saw the testing failed? How can I fix that?