Suggested typo corrections in "chapter4.txt"
Added new words to "glosario.txt"
Translated "es_chapter4.figures"->"capítulo4.figuras"
Translated "es_chapter4.txt"->"capítulo4.txt"

Note: The links to code files (e.g. http://invpy.com/adivinaElNúmero.py) may need to be corrected.
Just renamed "es_chapter4.txt" to "capítulo4.txt" (I forgot to do it before the previous commit)