Add Xiaomi Mi MIX 3 perseus markdown

Change-Id: Ifff634036bc0710bd206dc0d51b67b8207bb4161
diff --git a/_xiaomi/xiaomimix3.markdown b/_xiaomi/xiaomimix3.markdown
new file mode 100644
index 0000000..874c5c2
--- /dev/null
+++ b/_xiaomi/xiaomimix3.markdown
@@ -0,0 +1,25 @@
+---
+layout: device
+title:  "Xiaomi Mi MIX 3"
+codename: perseus
+downloadfolder: perseus
+supportstatus: Current
+maintainer: Mauronofrio
+devicetree: https://github.com/TeamWin/android_device_xiaomi_perseus
+oem: Xiaomi
+xdathread: "https://forum.xda-developers.com/mi-mix-3/development/recovery-unofficial-twrp-recovery-t3901261"
+---
+
+{% include disclaimer.html %}
+
+{% include supportstatus.html %}
+
+{% include xiaomiunlock.html %}
+
+{% include appinstall.html %}
+
+{% include download.html %}
+
+{% include twrpinstall.html %}
+
+{% include fastbootinstall.html %}