Feature/cleanup handbook
Minor cleanup, restructuring of discretization chapter (explain Finite Volumes first, own temporal discretization chapter), renaming of files (e.g. new numbering according to chapters). Resolves #635 (closed)
Minor cleanup, restructuring of discretization chapter (explain Finite Volumes first, own temporal discretization chapter), renaming of files (e.g. new numbering according to chapters). Resolves #635 (closed)