Update README.md

Author: alinelena

README.md

@@ -6,4 +6,4 @@ It is a simple helper for cases when one needs to download data in systems like
 ```python
 
   from data_tutorials.data import get_data
-  get_data(url="https://raw.githubusercontent.com/ddmms/data-tutorials/main/data/LiFePO4_supercell.cif", filename="LiFePO4_supercell.cif", folder="data")
+  get_data(url="https://raw.githubusercontent.com/ddmms/data-tutorials/main/data/", filename="LiFePO4_supercell.cif", folder="data")