feat(nvim): add oatmeal plugin to use ollama directly in Neovim

nvim/lua/plugins/oatmeal.lua

@@ -0,0 +1,11 @@
+return {
+  "dustinblackman/oatmeal.nvim",
+  cmd = { "Oatmeal" },
+  keys = {
+    { "<leader>om", mode = "n", desc = "Start Oatmeal session" },
+  },
+  opts = {
+    backend = "ollama",
+    model = "codellama:latest",
+  },
+}