update the templated network docs linear algebra (#1712)

we do not skip zeros, since we were doing that incorrectly previously

Docs/source/templated_networks.rst

@@ -384,16 +384,11 @@ Linear Algebra
 
 The VODE integrator needs routines to do LU factorization and back
 substitution.  We build off of the linpack ``dgefa`` and ``dgesl``
-routines, but because we know at compile time which Jacobian terms are
-non-zero, we are able to use ``constexpr`` for-loops to only do the
-calculations on non-zero elements.  This greatly reduces the amount of work
-in the linear algebra.
+routines, using ``constexpr`` for-loops that know the network size
+at compile time.
 
-Note:
-
-* Currently we are still storing a dense Jacobian -- we just skip computation
-  on the elements that are 0.
+.. note::
 
-* These routines do not perform pivoting.  This does not seem to be an
-  issue for the types of matrices we solve with reactions (since they are
-  all of the form :math:`I - \tau J`, where :math:`tau` is the timestep).
+   These routines do not perform pivoting.  This does not seem to be an
+   issue for the types of matrices we solve with reactions (since they are
+   all of the form :math:`I - \tau J`, where :math:`tau` is the timestep).