fix typo in rtd url

README.md

@@ -1,7 +1,7 @@
 # Visuomotor Serial Targeting Task (VSTT)
 
 [![PyPI](https://img.shields.io/pypi/v/vstt.svg)](https://pypi.org/project/vstt)
-[![Docs](https://readthedocs.org/projects/vstt/badge/?version=main)](https://vstt.readthedocs.io/en/latest/?badge=main)
+[![Docs](https://readthedocs.org/projects/vstt/badge/?version=main)](https://vstt.readthedocs.io)
 [![CI](https://github.com/ssciwr/vstt/actions/workflows/ci.yml/badge.svg)](https://github.com/ssciwr/vstt/actions/workflows/ci.yml)
 [![Coverage](https://codecov.io/gh/ssciwr/vstt/branch/main/graph/badge.svg?token=sjsAdTyLH1)](https://codecov.io/gh/ssciwr/vstt)
 [![Sonar](https://sonarcloud.io/api/project_badges/measure?project=ssciwr_vstt&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=ssciwr_vstt)