Added new TP to table of contents

ipynb/index.rst

@@ -29,4 +29,5 @@ Day 2
 - `pres111_intro_matplotlib <pres111_intro_matplotlib.slides.html>`_
 - `pres12_practical2 <pres12_practical2.slides.html>`_
 - `pres13_doc_applications <pres13_doc_applications.slides.html>`_
+- `pres15_data_manipulation_plotting <pres15_practical5.slides.html>`_
 - `practical_numpy_img_median <practical_numpy_img_median.slides.html>`_