fix some typo

Author: leimao

README.md

@@ -2,7 +2,7 @@
 
 ## Introduction
 
-`Bongard-LOGO` is a Python code repository with a purpose of generating synthetic [Bongard problems](https://en.wikipedia.org/wiki/Bongard_problem) in large scale with little human intervention. It mainly consists of a `Bongard-LOGO` dataset that has 12,000 synthetic Bongard problems, and a `bongard` Python library that is used for the synthesis of the Bongard problems. The user could use the `Bongard-LOGO` dataset for concept learning and symbolic learning, or use the `bongard` library for custom Bongard problem synthesis.
+`Bongard-LOGO` is a Python code repository with the purpose of generating synthetic [Bongard problems](https://en.wikipedia.org/wiki/Bongard_problem) on a large scale with little human intervention. It mainly consists of a `Bongard-LOGO` dataset that has 12,000 synthetic Bongard problems, and a `bongard` Python library that is used for the synthesis of the Bongard problems. The user could use the `Bongard-LOGO` dataset for concept learning and symbolic learning, or use the `bongard` library for custom Bongard problem synthesis.
 
 ## The `Bongard-LOGO` Dataset