feat: ufcs ranges sort example

examples/ufcs-ranges-sort/.gitignore

@@ -0,0 +1,2 @@
+# cpp2b cache directory
+.cache/cpp2

examples/ufcs-ranges-sort/build.cpp2

@@ -0,0 +1,4 @@
+import cpp2b.build;
+
+build: (inout b: cpp2b::build) -> void = {
+}

examples/ufcs-ranges-sort/ufcs-ranges-sort.cpp2

@@ -0,0 +1,10 @@
+main: () = {
+	a: std::array = (3, 1, 2);
+	a.std::ranges::sort();
+	for a do (n) {
+		std::println("{}", n);
+	}
+	assert(a[0] == 1);
+	assert(a[1] == 2);
+	assert(a[2] == 3);
+}