rename Airplane.export_xflr() to Airplane.export_XFLR5_xml()

CHANGELOG.md

@@ -40,6 +40,7 @@ Also, for at least one version before a breaking change, AeroSandbox development
 
 #### 4.1.5
 
+- PENDING DEPRECATION added: `asb.Airplane.export_XFLR()` has been renamed to `asb.Airplane.export_XFLR5_xml()`. This clarifies that the output is an XFLR5 XML file (which needs to be imported through the Plane menu in XFLR5), not an XFLR5 .xfl file - a point of user confusion. For now, both will work, but the old name will trigger a warning, and eventually will be removed. 
 - Added improvements to `asb.LiftingLine` to ensure mixed-backend compatibility.
 
 #### 4.1.4

aerosandbox/geometry/airplane.py

@@ -946,14 +946,28 @@ def export_AVL(self,
         )
         avl.write_avl(filepath=filename)
 
-    def export_XFLR(self,
-                    filename,
-                    mass_props: MassProperties = None,
-                    include_fuselages: bool = False,
-                    mainwing: Wing = None,
-                    elevator: Wing = None,
-                    fin: Wing = None,
-                    ):
+    def export_XFLR(self, *args, **kwargs):
+        import warnings
+
+        warnings.warn(
+            "`Airplane.export_XFLR()` has been renamed to `Airplane.export_XFLR5_xml()`, to clarify\n"
+            "that it exports to XFLR5's XML format, not to a XFL file.\n"
+            "\n"
+            "Please update your code to use `Airplane.export_XFLR5_xml()` instead.\n"
+            "\n"
+            "This function will be removed in a future version of AeroSandbox.",
+            PendingDeprecationWarning
+        )
+        return self.export_XFLR5_xml(*args, **kwargs)
+
+    def export_XFLR5_xml(self,
+                         filename,
+                         mass_props: MassProperties = None,
+                         include_fuselages: bool = False,
+                         mainwing: Wing = None,
+                         elevator: Wing = None,
+                         fin: Wing = None,
+                         ):
         """
         Exports the airplane geometry to an XFLR5 `.xml` file.
 
@@ -1398,4 +1412,4 @@ def ft(feet, inches=0):  # Converts feet (and inches) to meters
     )
 
     airplane.draw_three_view()
-    # airplane.export_XFLR("test.xml", mass_props=asb.MassProperties(mass=1, Ixx=1, Iyy=1, Izz=1))
+    # airplane.export_XFLR5_xml("test.xml", mass_props=asb.MassProperties(mass=1, Ixx=1, Iyy=1, Izz=1))