* doc(favicon): add documentation of favicon plugin
* doc(favicon): add missing link to configuration page
* fix(favicon): build on public folder don't created
* fix(transformer): find last modified date form commit on submodule
when the content folder has a submodule git, the relative path start in content folder and not root folder of quartz
* fix(transformer): use path.relative for improved path handling in last modified date calculation
* fix(transformer): keep find file from relative path of repo workdir
* fix(transformer): use variable for repository workdir
use default value if repo.workdir is undefined to user fullFp value
