Update challenge data package readme.txt

[coleslaw481]

Add this definition for hiTanimoto file:

[hiTanimoto-_-.pdb]
-- Candidate protein for docking which:
1) Passes the Blastnfilter criteria

                  2) Contains the Ligand with the highest structural similarity in Tanimoto 
                      score to the Target Ligand.

                     Note:  If multiple proteins founded, the protein
                            with the highest resolution will be picked.

[coleslaw481]

Fixed here:

07b7c76..221cb32 chrisdev -> chrisdev