twrpme: add gitactivity changelog tag to device markdowns

Change-Id: I437a42c1b2ccd79b3f85ad0962c362680c28d171
diff --git a/_devices/xiaomimax.markdown b/_devices/xiaomimax.markdown
index e3352fb..3ae86d9 100644
--- a/_devices/xiaomimax.markdown
+++ b/_devices/xiaomimax.markdown
@@ -5,6 +5,7 @@
 downloadfolder: hydrogen
 supportstatus: Current
 maintainer: Abdess
+devicetree: https://github.com/TeamWin/android_device_xiaomi_hydrogen.git
 oem: Xiaomi
 devicetree: https://github.com/TeamWin/android_device_xiaomi_hydrogen
 ---
@@ -19,5 +20,4 @@
 
 {% include twrpinstall.html %}
 
-
 {% include fastbootinstall.html %}