add message upon catching various errors to remind the user to instal…

…l necessary Python package requirements, which may not be present if the user installed anvi'o dev before this program was added

bin/anvi-draw-kegg-pathways

@@ -383,4 +383,12 @@ if __name__ == '__main__':
     except FilesNPathsError as e:
         print(e)
         sys.exit(-1)
-
+    except Exception as e:
+        print(
+            "Have you installed the necessary Python package requirements for "
+            "`anvi-draw-kegg-pathways`? This might be the cause of the error that was encountered, "
+            "reported below. Run the following command in your terminal and then try rerunning the "
+            "program:\npip install biopython ReportLab pymupdf frontend\n"
+        )
+        print(e)
+        sys.exit(-1)