Fix header levels in scripts/README.md

scripts/README.md

 tsplot
-------
+======
 
 The `tsplot` script is a wrapper around matplotlib for displaying a collection of
 time series plots.
@@ -79,7 +79,7 @@ Use the `-o` or `--output` option to save the plot as an image, instead of
 displaying it interactively.
 
 profstats
----------
+=========
 
 `profstats` collects the profiling data output from multiple MPI ranks and performs
 a simple statistical summary.
@@ -93,7 +93,7 @@ are reported instead.
 Output is in CSV format.
 
 PassiveCable.jl
----------------
+===============
 
 Compute analytic solutions to the simple passive cylindrical dendrite cable
 model with step current injection at one end from t=0.