[DOC] Reworked layout and pages

doc/additionalDoc/Chapters/creating-models.dox

doc/additionalDoc/Chapters/crtp.dox

doc/additionalDoc/Chapters/data-driven-algorithms.dox

doc/additionalDoc/Chapters/dynamic-algorithms.dox

doc/additionalDoc/Chapters/fcl-geometries.dox

doc/additionalDoc/Chapters/modeling-rigid-body.dox

doc/additionalDoc/Chapters/python-bindings.dox

doc/additionalDoc/Chapters/spatial-algebra.dox

doc/additionalDoc/GettingStarted/install.dox

doc/additionalDoc/GettingStarted/intro.dox

doc/additionalDoc/GettingStarted/simple-humanoid.dox

doc/additionalDoc/GettingStarted/urdf-loading-displaying.dox

doc/additionalDoc/users.dox

doc/layout.xml

doc/treeview.dox