Add a spain hyperlink

[SabrinaKZ]

No description provided.

[dpshelio]

This requires a bit of work.

1. It's required to add intermediate pages to link from continent to country, from country to region/city.
2. Links should be correct, not to the main wikipedia page
3. the branch name should be named accordingly you and your partner, no using the names of the instructors
4. The issue of the exercise needs to be referred in the body of the PR as instructed.