add mason autodownloader

lua/masonDownload.lua

@@ -0,0 +1,17 @@
+local pkgs = {
+	"nixpkgs-fmt",
+	"jdtls",
+    "yaml-language-server",
+    "eslint_d",
+}
+local reg = require("mason-registry")
+for  _, pname in ipairs(pkgs) do
+	local pkg = reg.get_package(pname)
+	if not pkg:is_installed() then
+		print(string.format("[masonDownload.lua]: %s is not installed. Installing.", pname))
+        local handle = pkg:install(nil)
+        --while handle.state ~= "CLOSED" do
+          --  print(handle.stdout)
+       -- end
+	end
+end