docs: move build instructions from README to BUILDING.md

- Move detailed setup and build instructions from README.md to BUILDING.md
- Add concise reference to BUILDING.md in README.md
- Keep testing and other documentation in README.md
- Improve organization of documentation by separating build-specific content

src/router/index.ts

@@ -286,7 +286,7 @@ const routes: Array<RouteRecordRaw> = [
 
 const isElectron = window.location.protocol === "file:";
 const initialPath = isElectron
-  ? window.location.pathname.split('/dist-electron/www/')[1] || '/'
+  ? window.location.pathname.split("/dist-electron/www/")[1] || "/"
   : window.location.pathname;
 
 const history = isElectron