DOC: Improve DataFrame.align docstring (#24631)

Author: Daniel Saxton

pandas/core/generic.py

@@ -8345,8 +8345,17 @@ def ranker(data):
         fill_value : scalar, default np.NaN
             Value to use for missing values. Defaults to NaN, but can be any
             "compatible" value
-        method : str, default None
+        method : {'backfill', 'bfill', 'pad', 'ffill', None}, default None
+            Method to use for filling holes in reindexed Series
+            pad / ffill: propagate last valid observation forward to next valid
+            backfill / bfill: use NEXT valid observation to fill gap
         limit : int, default None
+            If method is specified, this is the maximum number of consecutive
+            NaN values to forward/backward fill. In other words, if there is
+            a gap with more than this number of consecutive NaNs, it will only
+            be partially filled. If method is not specified, this is the
+            maximum number of entries along the entire axis where NaNs will be
+            filled. Must be greater than 0 if not None.
         fill_axis : %(axes_single_arg)s, default 0
             Filling axis, method and limit
         broadcast_axis : %(axes_single_arg)s, default None