Update Spanish translations with a few orthographic corrections

[dverbru]

#325

[rugk]

Hi @dverbru,
first of all, thanks for your first contribution to this project! 🎉 👍 🏅
I hope you'll like this project and enjoy hacking on it… 😃

Please subscribe to #138 to get notified for new updates on translations etc. 😃

BTW you can (automatically) let issues close when a PR is merged by adding some "magic" text to your PR body. (Manually linked it now.)

Also notice there are more things to translate like the add-on listings on AMO (addons.mozilla.org) etc. See the contributing guide for more information.

[rugk]

Requesting a potential review from @Fanksies and @bryancalisto. Unless there are objections, this will be merged soon.

@dverbru
To honor your work, you should be credited in the extension. To do that, you need to provide your name and a link in the extension.

You can credit yourself here and provide a link (in translatorLink) and a name (in translatorUsername). Also, you should add yourself to the CONTRIBUTORS.md file and the changelog as a translator to give credits here.

See https://github.com/TinyWebEx/common/blob/master/CONTRIBUTING.md#translations for how these placeholders are translated, especially the official doc.

BTW note if you want you can also write the Changelog entry already, just copy an existing one as explained as a side-note here.

[dverbru]

Added myself to CONTRIBUTORS file, thanks. Anything else?

[bryancalisto]

It looks good to me. Question marks consistent with Spanish conventions and overall semantically correct.

[rugk]

Fine, thanks a lot to everybody involved!