centred data fixes #118

Author: Pierre Alexandre Tremblay

Resources/Data/info.txt

@@ -7,4 +7,4 @@ Datasets:
 - line: A single thinly distributed line
 - mammoth: a 3d dataset in a shape of a mammoth (source: https://pair-code.github.io/understanding-umap/)
 - moon : Two overlapping crescent shapes
-- rays : Four rays as evenly distributed and clearly segregated slices
+- rays : Four rays as evenly distributed and clearly segregated slices, centred on zero.