DOC: Fix the aliases list for pygmt.grdclip (#4130)

Author: yvonnefroehlich

pygmt/helpers/decorators.py

@@ -420,6 +420,7 @@ def fmt_docstring(module_func):
         Select map :doc:`projection </projections/index>`.
     <BLANKLINE>
     **Aliases:**
+    <BLANKLINE>
     .. hlist::
        :columns: 3
     <BLANKLINE>

pygmt/src/grdclip.py

@@ -41,13 +41,14 @@ def grdclip(
     - Replace individual values with a new value
 
     Such operations are useful when you want all of a continent or an ocean to fall into
-    one color or gray shade in image processing, when clipping the range of data
-    values is required, or for reclassification of data values. The values can be any
-    number or NaN (Not a Number).
+    one color or gray shade in image processing, when clipping the range of data values
+    is required, or for reclassification of data values. The values can be any number or
+    NaN (Not a Number).
 
     Full GMT docs at :gmt-docs:`grdclip.html`.
 
     **Aliases:**
+
     .. hlist::
        :columns: 3