Fix minor virtual angle feature doc (#63)

README.md

@@ -450,8 +450,8 @@ N.B. All angular features are provided in [sin, cos] transformed form. E.g.: $\t
 | ----------- | ----------- | ----------- |
 | `residue_type` | One-hot encoding of amino acid type       |      21  |
 | `positional_encoding` | Transformer-like positional encoding of sequence position       |      16  |
-| `alpha` | Virtual torsion angle defined by four $C_\alpha$ atoms of residues $I_{-1},I,I_{+1},I_{+2}$       |      2  |
-| `kappa` | Virtual bond angle (bend angle) defined by the three $C_\alpha$ atoms of residues $I_{-2},I,_{+2}$       |      2  |
+| `alpha` | Virtual torsion angle defined by four $C_\alpha$ atoms of residues $I_{-1}, I, I_{+1}, I_{+2}$       |      2  |
+| `kappa` | Virtual bond angle (bend angle) defined by the three $C_\alpha$ atoms of residues $I_{-2}, I, I_{+2}$       |      2  |
 | `dihedrals` | Backbone dihedral angles $(\phi, \psi, \omega)$      |      6  |
 | `sidechain_torsions` | Sidechain torsion angles  $(\chi_{1-4})$     |    8    |