Add buffer deletion command and update source keymap, configure lsp_lines, null-ls, and trouble plugins

lua/custom/plugins/trouble.lua

@@ -0,0 +1,10 @@
+return {
+  "folke/trouble.nvim",
+  dependencies = {
+    "nvim-tree/nvim-web-devicons"
+  },
+  config = function()
+    require("trouble").setup {
+    }
+  end
+}