website: Add docs for REPLACE variables

userspace/ksud/src/installer.sh

@@ -277,6 +277,12 @@ mark_remove() {
   chmod 644 $1
 }
 
+mark_replace() {
+  mkdir -p ${1%/*} 2>/dev/null
+  setfattr -n trusted.overlay.opaque -v y $1
+  chmod 644 $1
+}
+
 request_size_check() {
   reqSizeM=`du -ms "$1" | cut -f1`
 }
@@ -390,7 +396,7 @@ install_module() {
   # Handle replace folders
   for TARGET in $REPLACE; do
     ui_print "- Replace target: $TARGET"
-    mktouch $MODPATH$TARGET/.replace
+    mark_replace $MODPATH$TARGET
   done
 
   # Handle remove files