add hpack

lua/config/hpack.lua

@@ -0,0 +1,12 @@
+local function hpack()
+    local file = vim.fn.expand("%")
+    local err = vim.fn.system("hpack " .. file)
+    if vim.v.shell_error ~= 0 then
+        print(err)
+    end
+end
+
+vim.api.nvim_create_autocmd("BufWritePost", {
+    pattern = "package.yaml",
+    callback = hpack,
+})