Set up crowdin

[tropicar]

The current crowdin configuration does not work because it's required to create of a folder with a similar structure of files for every language. How we have changed almost all the structure in the main language, this folder(its called i18n) gives an error when you try to build the project. Crowdin must be set up after all the documentation is done. We will set up crowdin for the next languages:

• English (main)
• Spanish
• German
• French

[pablomendezroyo]

@Marketen @dappnodedev We should retake the crowdin feature in the new documentation