add debug docs

DEBUG_README.md

@@ -0,0 +1,28 @@
+## build and debug
+```
+./gradlew installDebug
+```
+## reboot (not needed after debug install)
+```
+adb reboot
+```
+
+## adb logs
+```
+adb logcat | grep -i "BringBackQSTitles"
+```
+
+## restart systemUI
+```
+adb shell su -c 'killall com.android.systemui'
+```
+
+## expand quick settings
+```
+adb shell cmd statusbar expand-settings
+```
+
+## screenshot
+```
+adb exec-out screencap -p > screenshot.png
+```