docs: mention config file

README.md

@@ -3,7 +3,8 @@
 Opinionated key remapper that brings sticky keys functionality like Android's
 AOSP keyboard to Linux.
 
-## Core Logic
+
+## Behavior
 
 For a modifier key `M`, the following table illustrates latching and locking.
 On first run all keys are unlatched.
@@ -15,6 +16,11 @@ Latched | < 500ms | Locked
 Latched | >= 500ms | Unlatched
 Locked | Whenever | Unlatched
 
+## Features
+- Ridiculously fast.
+- Release binary size is smaller than an average wallpaper.
+- Simple `ini` config file with example provided in the repo.
+
 ## Getting Started
 
 ### Build