Update README.md

README.md

 # Nuchart
 This project extracts mass excesses, various Q-values and separation energies, 
-half-lives, spins and parities of all nuclides documented in the *AME* and *NUBASE* 
-data tables of 2016.
-The extracted values are stored in a *ROOT* tree called ***nuchart.root***.
+half-lives, spins and parities of all nuclides documented in the ***AME*** and 
+***NUBASE*** data tables of 2016.
+
+The values are extracted in ***datagetter.py*** and written to a *ROOT* tree in 
+***treemaker.py***.
+The resulting ROOT tree is called ***nuchart.root***.
 
 It is possible to expand the tree with more values derived from the values already 
 present in the tree.