added dask and numba lesson link to python chapter

Author: DrDaveTurner

episodes/performance-concepts.md

@@ -329,7 +329,7 @@ How much faster should it be?
 
 Run the dot_product.R code several times to get an average
 execution time for a dot product between two vectors of
-1 million elements each.  Try to run them on an isolated system
+10 million elements each.  Try to run them on an isolated system
 if possible, or through a batch queue that at least ensures the
 code is being run on an isolated processing core.
 Then run the dot_product_sparse.R code in the same manner for

episodes/python.md

@@ -406,6 +406,7 @@ If you do this please contribute your code and timings.
 * [Scikit]()
 * [Dask](https://dask.org)
 * [Numba](https://numba.pydata.org)
+* [Software Carpentry Incubator lesson with Dask and Numba](https://carpentries-incubator.github.io/lesson-parallel-python/)
 * [Parsl python package](https://github.com/Parsl/parsl)