add buildx script

bin/buildx

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+target=$(rustc --print target-list | fzf --cycle --header "Select build target:")
+
+if [ -z "$target" ]; then
+    echo "No target selected. Canceled."
+    exit 1
+fi
+
+if [ -n "$1" ]; then
+    cmd="$1"
+    shift
+else
+    cmd="build"
+fi
+
+cross "$cmd" --target "$target" $@