minor DS wording issues.

[umlaeute]

• doc/4.data.structures/01.scalars.pd -> [pd template1]

  "graph no parent"

  i think this should read on rather than no

• various help-patches in doc/5.reference/ mention

  the 4.Data.Structure section

  but the docs only have a directory 4.data.structures (notice capitalization and plural)

• a subset of these help-patches says:

  the 4.Data.Structure section of the Pd's tutorials

  i think this should read of Pd's tutorials or of the Pd tutorials

  (and maybe use singular tutorial or even documentation, but that's probably a matter of taste)