install a bunch of default mason plugins

lua/plugins/mason.lua

@@ -0,0 +1,21 @@
+return {
+  {
+    "williamboman/mason.nvim",
+    opts = {
+      ensure_installed = {
+        "delve",
+        "gofumpt",
+        "goimports",
+        "gopls",
+        "json-lsp",
+        "lua-language-server",
+        "markdown-toc",
+        "markdownlint-cli2",
+        "marksman",
+        "shfmt",
+        "stylua",
+        "tree-sitter-cli",
+      },
+    },
+  },
+}