feat: spanish docs added on landing page

[ezegavilan]

Description
Spanish docs added on skaffold landing page. The idea is to allow multiple languages on the skaffold's documentation to make it easier for developers across the world.

Follow-up Work
Translate Skaffold "Install Skaffold" and "Quickstart" Documentation to Spanish, and then iterate over all the documentation pages.

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[alphanota]

Hi @ezegavilan, thank you for your pull-request, but I don't think this PR can be merged at this time, for the following reasons:

1. Large number of changes (150 documentation files added), making this really hard to review.
2. The vast majority of the new documentation is still in english, so its not really fulfilling the objective of this PR.

Regards.