Improve clarity

Author: tovrstra

README.md

@@ -40,7 +40,7 @@ pip install tinyff
 Code written for TinyFF 1 can be easily updated to work with TinyFF 2.
 All required changes are documented in the [Migration Guide](migration.md).
 
-A complete list of changes is documented in [CHANGELOG.md](CHANGELOG.md).
+A complete list of changes can be found in [CHANGELOG.md](CHANGELOG.md).
 
 
 ## Features

migration.md

@@ -5,7 +5,7 @@ Minor versions upgrades should maintain backward compatibility.
 Only when the major version changes, you may need to make changes to code using TinyFF
 
 
-## Upgrading from TinyFF 1.x to 2.x
+## Upgrading from TinyFF 1 to 2
 
 The required changes are relatively minor:
 
@@ -59,7 +59,6 @@ The required changes are relatively minor:
 - The pair potentials have undergone a similar change.
   If you want to calculate the derivative, you need to ask for it explicitly.
   By default, only the energy is computed.
-  (They are now all derived from `PairwiseTerm` instead of `PairPotential`)
   For example, change from:
 
     ```python