Update README.md

Author: evasseure

README.md

@@ -52,6 +52,7 @@ Words: 5
 Words per second: 47.88 word/s
 
 ## Further improvements
+- [ ] Improve handling of big files    
 - [ ] Setup a Phoenix front-end  
 - [ ] Use a Rust NIF to improve speed? (See [#1](https://github.com/evasseure/checkcheckcheck/pull/1))  
 - [ ] Sort suggestions by probability