Update 00-preface.tex
00-preface.tx

This file is ready for proofreading.
Revert "Update 00-preface.tex"

This reverts commit 274c310cb39a9071990ba183472d945c4293fbb8.
resolve conflict
Proofreading change

Chaged "diciembre" to lower case
Merge branch 'master' of https://github.com/hedemarrie/py4inf-esp