message: Fix link in docu
diff: [data]: documentation.html#data
  [GeometricModel]: documentation.html#geometricmodels
  [VolumetricModel]: documentation.html#volumetricmodels
  -[texture transformations]: documentation.html#texture2d-transformations
  +[texture transformations]: documentation.html#texture-transformations
  [renderer]: documentation.html#renderers
  [SciVis renderer]: documentation.html#scivis-renderer
  [path tracer]: documentation.html#path-tracer
  