etl: add package (#2524)

* etl: add package

* fix test

packages/e/etl/xmake.lua

@@ -0,0 +1,25 @@
+package("etl")
+    set_kind("library", {headeronly = true})
+    set_homepage("https://www.etlcpp.com")
+    set_description("Embedded Template Library")
+    set_license("MIT")
+
+    add_urls("https://github.com/ETLCPP/etl/archive/refs/tags/$(version).tar.gz",
+             "https://github.com/ETLCPP/etl.git")
+
+    add_versions("20.38.0", "7e29ce81a2a2d5826286502a2ad5bde1f4b591d2c9e0ef7ccc335e75445223cd")
+
+    add_deps("cmake")
+
+    on_install(function (package)
+        import("package.tools.cmake").install(package, configs)
+    end)
+
+    on_test(function (package)
+        assert(package:check_cxxsnippets({test = [[
+            #include <etl/array.h>
+            void test() {
+                etl::array<int, 10> data = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
+            }
+        ]]}, {configs = {languages = "c++11"}}))
+    end)