Fix docstring for histtype (#514)

Author: cverstege

src/mplhep/plot.py

@@ -121,7 +121,7 @@ def histplot(
 
             - "step": skyline/step/outline of a histogram using `plt.stairs <https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.stairs.html#matplotlib-axes-axes-stairs>`_
             - "fill": filled histogram using `plt.stairs <https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.stairs.html#matplotlib-axes-axes-stairs>`_
-            - "step": filled band spanning the yerr range of the histogram using `plt.stairs <https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.stairs.html#matplotlib-axes-axes-stairs>`_
+            - "band": filled band spanning the yerr range of the histogram using `plt.stairs <https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.stairs.html#matplotlib-axes-axes-stairs>`_
             - "errorbar": single marker histogram using `plt.errorbar <https://matplotlib.org/stable/api/_as_gen/matplotlib.axes.Axes.errorbar.html#matplotlib-axes-axes-errorbar>`_
         xerr:  bool or float, optional
             Size of xerr if ``histtype == 'errorbar'``. If ``True``, bin-width will be used.