nvim: fix trouble conf, remove hierarchy-tree-go, split init.lua

nvim/.config/nvim/lua/plugins/file-explorer.lua

@@ -0,0 +1,13 @@
+return {
+  {
+    'stevearc/oil.nvim',
+    dependencies = { "nvim-tree/nvim-web-devicons" },
+    opts = {
+      default_file_explorer = true,
+      delete_to_trash = true,
+    },
+    keys = {
+      { "<leader>-", "<cmd>Oil --float<CR>", desc = "Open parent directory" },
+    },
+  },
+}