rsync: add plugin

plugins/rsync/rsync.plugin.zsh

+function copy {
+    rsync -av --progress -h "$1" "$2"
+}
+
+function move {
+    rsync -av --progress -h --remove-source-files "$1" "$2"
+}
+
+function update {
+    rsync -avu --progress -h "$1" "$2"
+}
+
+function synchronize {
+    rsync -avu --delete --progress -h "$1" "$2"
+}