refactor(nvim): pass theme setting to themes.lua

neovim/default.nix

@@ -162,8 +162,10 @@
             ${builtins.readFile ./nvim-cmp.lua }
             ${builtins.readFile ./telescope.lua }
 
-            ${builtins.readFile ./themes.lua }
-            vim.opt.background = '${theme}'
+            do
+              local vim_theme = "${theme}";
+              ${builtins.readFile ./themes.lua }
+            end
 
             ${builtins.readFile ./project-nvim.lua }
             ${builtins.readFile ./dap.lua }

neovim/themes.lua

@@ -1 +1,2 @@
 vim.cmd("colorscheme solarized")
+vim.opt.background = vim_theme