neovim: add nvim-lint plugin

roles/configure/files/config/nvim/lua/plugins/lint.lua

@@ -0,0 +1,15 @@
+return {
+  "mfussenegger/nvim-lint",
+  config = function()
+    require("lint").linters_by_ft = {
+      ["yaml.github"] = { "actionlint" },
+    }
+
+    vim.api.nvim_create_autocmd("BufWritePost", {
+      pattern = "*",
+      callback = function()
+        require("lint").try_lint()
+      end,
+    })
+  end,
+}