Add Star History section to README

Added Star History section with a chart link.

Author: tianzhou

README.md

@@ -76,3 +76,7 @@ go test ./parser/pgregress -run TestPGRegressStats -v
 ## License
 
 This project is licensed under the MIT License. Portions derived from PostgreSQL are subject to the PostgreSQL License.
+
+## Star History
+
+[![Star History Chart](https://api.star-history.com/svg?repos=bytebase/pgparser&type=date&legend=top-left)](https://www.star-history.com/#bytebase/pgparser&type=date&legend=top-left)