Tutorials support English and Spanish

[felixminom]

This WIP PR resolves stackbuilders/stackbuilders.com#958

In order to keep the format of routes (ex: /es/services) I have added a /es directory that contains all templates and files needed to keep this behavior. It was needed tutorial.md to be duplicated in this /es directory to be able to create a new route that contains the /es prefix, this is why this PR contains a lot of files added.

This is how site looks now.

TODO:

• Update contributing guideline.
• Create tags' spanish version.

Could you take a look a this, please ? @sestrella @jpvillaisaza

[cptrodolfox]

I will continue working on this PRs based on the work done by @felixminom .

[cptrodolfox]

I will have to pause as the complexity of this PR is too great at the moment. However, I have updated the work done so far.

What works:

• Creation of Spanish and English version routes from the same tutorial file.
• Spanish version of the tags for both english and Spanish.
• Proper Spanish context for this tag indexes given by the html template /es/templates/tutorials-list.html and proper title.

What does not work:

• Tags inside Spanish version of the tutorials link to the English version of the tag indices.

Future work:

• Use a file extension hierarchy to create Spanish and English version of the tutorials (*.es.md and *.md). If a .es.md version of the file is found use that one to create the Spanish tutorial, instead of the .md version.