twrpme: Add an include for AVB

Change-Id: I77d6dd1da80ecfcf76d95bf74f0fdd2290db94d9
diff --git a/_includes/avb.html b/_includes/avb.html
new file mode 100644
index 0000000..6a49ee3
--- /dev/null
+++ b/_includes/avb.html
@@ -0,0 +1,3 @@
+<div class='page-heading'>This device uses Android Verified Boot (AVB)</div>
+<hr />
+<p class="text">This means that installing TWRP or swiping to allow system modifications will prevent you from being able to boot. To bypass AVB's boot prevention, you will have to disable it or install a custom ROM that ships with disabled AVB.</p>