docs(all): incorrect path for registering plugin in rust (#2123)

Committed via a GitHub action: https://github.com/tauri-apps/plugins-workspace/actions/runs/12127198045

Co-authored-by: FabianLars <[email protected]>

README.md

@@ -55,7 +55,7 @@ yarn add https://github.com/tauri-apps/tauri-plugin-updater#v2
 
 First you need to register the core plugin with Tauri:
 
-`src-tauri/src/main.rs`
+`src-tauri/src/lib.rs`
 
 ```rust
 fn main() {