Translated chapter 1 and chapter 1 figures to German.
Updated translations/de/README.md:
- Updated the list of translators
- Translated the book's title
- Added difficult to translate terms to the 'General Notes' section for peer review
Added github user names to the list of German translators.
Merge remote-tracking branch 'upstream/master'
Updated the list of German translators.
Merge remote-tracking branch 'upstream/master'
Merge pull request #36 from denniskb/master

Chapter 1 translated to German.