feat(lang): add R support

lua/lazyvim/plugins/extras/lang/r.lua

@@ -0,0 +1,30 @@
+return {
+  {
+    "nvim-treesitter/nvim-treesitter",
+    opts = function(_, opts)
+      if type(opts.ensure_installed) == "table" then
+        vim.list_extend(opts.ensure_installed, { "r" })
+      end
+    end,
+  },
+  {
+    "neovim/nvim-lspconfig",
+    opts = {
+      servers = {
+        r_language_server = {},
+      },
+    },
+  },
+  {
+    "nvim-neotest/neotest",
+    optional = true,
+    dependencies = {
+      "shunsambongi/neotest-testthat",
+    },
+    opts = {
+      adapters = {
+        ["neotest-testthat"] = {},
+      },
+    },
+  },
+}