[cs] Typos and formulation changes in Ch. 1 up to 1.3 included.
Merge branch 'master' of https://github.com/progit/progit.git
[cs] changes to Chapter 1, section 1.4
Merge branch 'master' of https://github.com/progit/progit.git
Merge branch 'HEAD' of git@github.com:pepr/progit.git
[cs] the empty cs/09-git-internals/02-translation-notes.markdown added

The reason is to try overwrite incorectly rendered content.
Merge pull request #764 from pepr/master

[cs] Several corrections and additions to the content + plus the experiment to solve #762