message: Link to OFF file format in example section
diff: @@ -178,7 +178,7 @@ In the following example, a threshold of :math:`\alpha^2 = 32.0` is used.
  Example from OFF file
  ^^^^^^^^^^^^^^^^^^^^^
  -This example builds the alpha complex from 300 random points on a 2-torus.
  +This example builds the alpha complex from 300 random points on a 2-torus, given by an `OFF file <fileformats.html#off-file-format>`_.
  Then, it computes the persistence diagram and displays it:
  