Update docs/source/core_engine/01-flags.md

Co-authored-by: Glenn Matthews <glenn.matthews@networktocode.com>

Author: dgarros

docs/source/core_engine/01-flags.md

@@ -1,5 +1,5 @@
 
-The Core Engine of DiffSync is meant to be transparent for most users but in some cases it's important to have the ability to change it's behavior to adjust to some specific use cases. For these use cases, there are few methods available to customize its behavior:
+The core engine of DiffSync is meant to be transparent for most users but in some cases it's important to have the ability to change its behavior to adjust to some specific use cases. For these use cases, there are several ways to customize its behavior:
  - Global and Model Flags
  - Diff class