make it clearer that kwant supports any number of dimensions

doc/source/tutorial/introduction.rst

@@ -46,3 +46,9 @@ The typical workflow with kwant is as follows:
 #. Attach leads (tight binding systems with translational symmetry).
 
 #. Pass the finalized system to a solver.
+
+Please note that even though this tutorial only shows 2-d systems, kwant is
+completely general with respect to the number of dimensions.  kwant does not
+care in the least whether systems live in one, two, three, or any other number
+of dimensions.  The only exception is plotting, which out-of-the-box only works
+for up to three dimensions.  (But custom projections can be specified!)

kwant/lattice.py

@@ -11,14 +11,15 @@ from . import builder
 
 def make_lattice(prim_vecs, basis=None):
     """
-    Create a Bravais lattice, which may have more than one basis site.
+    Create a Bravais lattice of any dimensionality, with any number of basis
+    sites.
 
     Parameters
     ----------
     prim_vecs : sequence of sequences of floats
-        Primitive vectors of a Bravais lattice.
+        The primitive vectors of the Bravais lattice.
     basis : sequence of floats
-        Coordinates of the basis sites inside the unit cell.
+        The coordinates of the basis sites inside the unit cell.
 
     Returns
     -------