Hi German,
Thanks for your suggestion to add more language links to http://docs.moodle.org/. I have added all the languages you list, except for Brazilan Portuguese, which didn't work (needs investigating).
For inter-language links to appear in the 'In other languages' block, they have to be of the format [[es:Página Principal]], thus for languages with more than one wiki, only the most recent wiki be linked to, which I think makes sense.