adding a gitignore, so that all the results, compilation files and so on are...

adding a gitignore, so that all the results, compilation files and so on are not pushed to the repository

.gitignore

+bin1D/
+mod1D/
+obj1D/
+bin2D/
+mod2D/
+obj2D/
+bin2D.2/
+mod2D.2/
+obj2D.2/
+*.plt
+*.err
+fort.[0-9]
+*.dat
+*.sol
+*.pdfa