feat(plugins): Add file tree, Enable Lazy loading

I've tried to lazy load most the plugins to improve start up time.
It has been greatly reduced, from more than 600ms to just around 100ms

Bug: Line that shows up when you are inside a block(block-line) doesn't
have color.

lua/kickstart/plugins/debug.lua

@@ -7,9 +7,7 @@
 -- kickstart.nvim and not kitchen-sink.nvim ;)
 
 return {
-  -- NOTE: Yes, you can install new plugins here!
   'mfussenegger/nvim-dap',
-  -- NOTE: And you can specify dependencies as well
   dependencies = {
     -- Creates a beautiful debugger UI
     'rcarriga/nvim-dap-ui',
@@ -21,6 +19,7 @@ return {
     -- Add your own debuggers here
     'leoluz/nvim-dap-go',
   },
+  event = { 'BufReadPre', 'BufNewFile' },
   config = function()
     local dap = require 'dap'
     local dapui = require 'dapui'