README: expand build commands

Author: vaxerski

README.md

@@ -43,8 +43,8 @@ will make those events ignored.
 
 ### Building:
 ```sh
-cmake --no-warn-unused-cli -DCMAKE_BUILD_TYPE:STRING=Release -S . -B ./build
-cmake --build ./build --config Release --target hypridle -j`nproc 2>/dev/null || getconf _NPROCESSORS_CONF`
+cmake --no-warn-unused-cli -DCMAKE_BUILD_TYPE:STRING=Release -DCMAKE_INSTALL_PREFIX:PATH=/usr -S . -B ./build
+cmake --build ./build --config Release --target all -j`nproc 2>/dev/null || getconf NPROCESSORS_CONF`
 ```
 
 ### Installation: