Apply suggestions from code review

Co-authored-by: Meghan Jones <meghanj@alum.mit.edu>

Author: willschlitzer

pygmt/src/basemap.py

@@ -52,7 +52,6 @@ def basemap(self, **kwargs):
     Parameters
     ----------
     {J}
-        *Required if this is the first plot command.*
     zscale/zsize : float or str
         Set z-axis scaling or z-axis size.
     {R}

pygmt/src/coast.py

@@ -64,7 +64,6 @@ def coast(self, **kwargs):
     Parameters
     ----------
     {J}
-        *Required if this is the first plot command.*
     {R}
         *Required if this is the first plot command.*
     {A}

pygmt/src/text.py

@@ -116,7 +116,6 @@ def text_(
         left. If no justification is explicitly given (i.e. ``justify=True``),
         then the input to ``textfiles`` must have this as a column.
     {J}
-        *Required if this is the first plot command.*
     {R}
         *Required if this is the first plot command.*
     clearance : str