Update installation link in README.md

The previous link resulted in a 404. Other ways to fix this issue would be to either remove this link or create a redirect (perhaps the most robust).

Author: siemensikkema

README.md

@@ -18,7 +18,7 @@ src="https://img.shields.io/github/stars/editor-code-assistant/eca?style=flat-sq
 
 <hr>
 <p align="center">
-  <a href="https://eca.dev/installation"><strong>installation</strong></a> •
+  <a href="https://eca.dev/config/introduction/#installation"><strong>installation</strong></a> •
   <a href="https://eca.dev/features"><strong>features</strong></a> •
   <a href="https://eca.dev/config/introduction"><strong>configuration</strong></a> •
   <a href="https://eca.dev/config/models"><strong>models</strong></a> •