add miniaudio (#825)

packages/m/miniaudio/xmake.lua

@@ -0,0 +1,15 @@
+package("miniaudio")
+    set_kind("library", {headeronly = true})
+    set_homepage("https://miniaud.io")
+    set_description("Single file audio playback and capture library written in C.")
+
+    add_urls("https://github.com/mackron/miniaudio.git")
+    add_versions("2021.12.31", "42abbbea4602af80d1ccb4a22cdc35813aceee7a")
+
+    on_install(function (package)
+        os.cp("miniaudio.h", package:installdir("include"))
+    end)
+
+    on_test(function (package)
+        assert(package:has_cfuncs("ma_encoder_config_init", {includes = "miniaudio.h"}))
+    end)