DOC: Fix typos for v0.16.0 (#3972)

Author: yvonnefroehlich

pygmt/src/grd2cpt.py

@@ -82,10 +82,10 @@ def grd2cpt(grid: PathLike | xr.DataArray, **kwargs):
     Parameters
     ----------
     {grid}
-    transparency : int or float or str
-        Set a constant level of transparency (0-100) for all color slices.
-        Append **+a** to also affect the foreground, background, and NaN
-        colors [Default is no transparency, i.e., ``0`` (opaque)].
+    transparency : float or str
+        Set a constant level of transparency (0-100) for all color slices. Append **+a**
+        to also affect the foreground, background, and NaN colors [Default is no
+        transparency, i.e., ``0`` (opaque)].
     cmap : str
         Select the master color palette table (CPT) to use in the
         interpolation. Full list of built-in color palette tables can be found

pygmt/src/makecpt.py

@@ -70,10 +70,10 @@ def makecpt(**kwargs):
 
     Parameters
     ----------
-    transparency : str
-        Set a constant level of transparency (0-100) for all color slices.
-        Append **+a** to also affect the foreground, background, and NaN
-        colors [Default is no transparency, i.e., ``0`` (opaque)].
+    transparency : float or str
+        Set a constant level of transparency (0-100) for all color slices. Append **+a**
+        to also affect the foreground, background, and NaN colors [Default is no
+        transparency, i.e., ``0`` (opaque)].
     cmap : str
         Select the master color palette table (CPT) to use in the
         interpolation. Full list of built-in color palette tables can be found