Merge branch 'release/1.9.11' into develop
Add the book cover to the assets
Add the centered cover images
Update the windmill submodule
Fix a link in the index page.
Update the README file
Merge branch 'feature/update-jekyll-config' into develop

* feature/update-jekyll-config:
  Update the README file
  Fix a link in the index page.
  Update the windmill submodule
  Add the centered cover images
  Add the book cover to the assets
Update the version number
Update the dist files
Merge branch 'release/2.0.0'

* release/2.0.0:
  Update the dist files
  Update the version number
  Update the README file
  Fix a link in the index page.
  Update the windmill submodule
  Add the centered cover images
  Add the book cover to the assets