Add cmcrameri citation suggestions to docstrings

doped/chemical_potentials.py

@@ -2808,6 +2808,9 @@ def plot_chempot_heatmap(
         This is only the case for ``png`` output, so saving to e.g. ``svg`` or
         ``pdf`` instead will avoid this issue.
 
+        If using the default colour map (``batlow``) in publications, please
+        consider citing: https://zenodo.org/records/8409685
+
         Args:
             dependent_element (str or Element):
                 The element for which the chemical potential is plotted as a

doped/thermodynamics.py

@@ -2673,7 +2673,7 @@ def plot(
                 colormap from the latter) or a ``Colormap`` / ``ListedColormap`` object.
                 If ``None`` (default), uses ``tab10`` with ``alpha=0.75`` (if 10 or fewer
                 lines to plot), ``tab20`` (if 20 or fewer lines) or ``batlow`` (if more
-                than 20 lines).
+                than 20 lines; citation: https://zenodo.org/records/8409685).
             linestyles (list):
                 Linestyles to use for the formation energy lines, either as a single
                 linestyle (``str``) or list of linestyles (``list[str]``) in the order of

doped/utils/plotting.py

@@ -61,6 +61,8 @@ def get_colormap(colormap: Optional[Union[str, Colormap]] = None, default: str =
 
     If ``_alpha_X`` in the colormap name, sets the alpha value to X (0-1).
 
+    ``cmcrameri`` colour maps citation: https://zenodo.org/records/8409685
+
     Args:
         colormap (str, matplotlib.colors.Colormap):
             Colormap to use, either as a string (which can be a colormap name