Improve consistency in VTK File Formats docs

HDF5 examples

The first HDF5 lines in example h5dump outputs were updated. Assumption: h5dump is run for the canonical relative paths from the VTK root as the working directory.

A wrong brace pairing was fixed. (moved from vtk-examples!319 (closed))

Headings (pointed out by @amaclean)

Now the headings end without a period "." for all headings.