Added index (auto-generated).

_toc.yml

@@ -9,6 +9,7 @@ parts:
     chapters:
     - file: content/markdown
     - file: content/interactivemarkdown
+    - file: content/testfile
     - file: content/jupyterquiz.md
   - caption: Demonstrating Jupyter notebooks
     numbered: True
@@ -18,5 +19,7 @@ parts:
     numbered: True
     chapters:
     - file: content/git
-
+  - caption: Index
+    chapters:
+    - file: genindex
     
\ No newline at end of file

content/interactivemarkdown.md

@@ -14,12 +14,15 @@ kernelspec:
 ## Plots
 
 In a printed book, graphs can be included as figures. We can do the same in an online book, but we can also do much more. The simplest extension is to not create a figure file which we include, but to create the figure from code. The upshot of this approach is that students can go in and see how the figure is made. For example, {numref}`fig:free_energy_density` below shows the van der Waals free energy density, 
-
+```{index} Van der Waals free energy density
+```
 $$
 f_\mathrm{VdW}(\rho) = k_\mathrm{B} T \rho \left[\ln\left(\frac{\rho}{1-b \rho}\right) - 1\right] - a \rho^2,
 $$ (VdWfreeenergydensity)
 
 combined with the common tangent construction to obtain the densities of coexisting phases.
+```{index} common tangent construction.
+```
 
 ```{code-cell} ipython3
 :tags: [hide-input, remove-output]
@@ -142,6 +145,9 @@ line with the same slope.
 
 ## Interactive plots
 
+```{index} interactive plots
+```
+
 We can make the plot in {numref}`fig:free_energy_density` even more useful by making it interactive, letting students see how the plot changes if we change a parameter, *without* having to dive in the code. The interactive version is shown in the figure below.
 
 ```{code-cell} ipython3

genindex.md

+# Index