doc(readme): improvements

README.md

@@ -66,7 +66,8 @@ The [`PreLiquidationAddressLib`](./src/libraries/periphery/PreLiquidationAddress
 
 ### Potential preLCF manipulation
 
-A pre-liquidation cannot pre-liquidate a proportion of the position's debt greater than `preLCF`, however it's possible to pre-liquidate a proportion of the position while keeping it pre-liquidatable before performing another pre-liquidation.
+A pre-liquidation cannot repay a proportion of the position's debt greater than `preLCF`.
+However it's possible to pre-liquidate a proportion of the position while keeping it pre-liquidatable before performing another pre-liquidation.
 This manipulation can lead to repaying a proportion of the position's debt higher than `preLCF`.
 It has been studied in the part 5.2 of [An Empirical Study of DeFi Liquidations:Incentives, Risks, and Instabilities](https://arxiv.org/pdf/2106.06389), in the case of a constant liquidation close factor.
 Implementing a `preLCF` linear in the health factor can help mitigating this manipulation when choosing the right slope.