add link to the tutorials

docs/features.md

@@ -178,4 +178,4 @@ Nonbond energies are set to 0 for any atom pairs (on the same chain) that are wi
 
 Charge and vanderwaals parameters are set to 0 for those atoms that are unknown to the OPLS forcefield, treating such cases as missing values. If this happens for many of the atoms in the PDB file/s provided, depending on the specific dataset it may be worth it to drop the features affected, i.e., `electrostatic`, `vanderwaals`, and `atom_charge`.
 
-- It may be useful to generate histograms of the processed data to further investigate the distribution of these features' values before deciding whether to drop them. Refer to the `data_generation_xxx.ipynb` tutorial files for comprehensive instructions on transforming the data into a Pandas dataframe and generating histograms of the features.
+- It may be useful to generate histograms of the processed data to further investigate the distribution of these features' values before deciding whether to drop them. Refer to the `data_generation_xxx.ipynb` [tutorial files](https://github.com/DeepRank/deeprank2/tree/main/tutorials) for comprehensive instructions on transforming the data into a Pandas dataframe and generating histograms of the features.