mustache: add package (#2512)

packages/m/mustache/xmake.lua

@@ -0,0 +1,22 @@
+package("mustache")
+    set_kind("library", {headeronly = true})
+    set_homepage("https://github.com/kainjow/Mustache")
+    set_description("Mustache text templates for modern C++")
+    set_license("BSL-1.0")
+
+    add_urls("https://github.com/kainjow/Mustache.git")
+    add_versions("2021.12.10", "04277d5552c6e46bee41a946b7d175a660ea1b3d")
+
+    on_install(function (package)
+        os.cp("mustache.hpp", package:installdir("include"))
+    end)
+
+    on_test(function (package)
+        assert(package:check_cxxsnippets({test = [[
+            #include <mustache.hpp>
+            using namespace kainjow::mustache;
+            void test() {
+                mustache tmpl{"Hello {{what}}!"};
+            }
+        ]]}, {configs = {languages = "c++11"}}))
+    end)