Fix error to link in table

Author: tsmbland

docs/user-guide/index.rst

@@ -52,4 +52,4 @@ We have also provided links to the input and results files for each of the tutor
       - `[7] <https://github.com/EnergySystemsModellingLab/MUSE_OS/tree/main/docs/tutorial-code/7-add-correlation-demand>`_
    *  - 8
       - :ref:`/user-guide/carbon-budget.ipynb`
-      - `[7] <https://github.com/EnergySystemsModellingLab/MUSE_OS/tree/main/docs/tutorial-code/8-carbon-budget>`_
+      - `[8] <https://github.com/EnergySystemsModellingLab/MUSE_OS/tree/main/docs/tutorial-code/8-carbon-budget>`_