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/git.lua

@@ -0,0 +1,80 @@
+return {
+  -- Adds git related signs to the gutter, as well as utilities for managing changes
+  'lewis6991/gitsigns.nvim',
+  dependencies = {
+    -- Git related plugins
+    'tpope/vim-fugitive',
+    'tpope/vim-rhubarb',
+  },
+  event = { 'BufReadPre', 'BufNewFile' },
+  opts = {
+    -- See `:help gitsigns.txt`
+    signs = {
+      add = { text = '+' },
+      change = { text = '~' },
+      delete = { text = '_' },
+      topdelete = { text = '‾' },
+      changedelete = { text = '~' },
+    },
+    on_attach = function(bufnr)
+      local gs = package.loaded.gitsigns
+
+      local function map(mode, l, r, opts)
+        opts = opts or {}
+        opts.buffer = bufnr
+        vim.keymap.set(mode, l, r, opts)
+      end
+
+      -- Navigation
+      map({ 'n', 'v' }, ']c', function()
+        if vim.wo.diff then
+          return ']c'
+        end
+        vim.schedule(function()
+          gs.next_hunk()
+        end)
+        return '<Ignore>'
+      end, { expr = true, desc = 'Jump to next hunk' })
+
+      map({ 'n', 'v' }, '[c', function()
+        if vim.wo.diff then
+          return '[c'
+        end
+        vim.schedule(function()
+          gs.prev_hunk()
+        end)
+        return '<Ignore>'
+      end, { expr = true, desc = 'Jump to previous hunk' })
+
+      -- Actions
+      -- visual mode
+      map('v', '<leader>hs', function()
+        gs.stage_hunk { vim.fn.line '.', vim.fn.line 'v' }
+      end, { desc = 'stage git hunk' })
+      map('v', '<leader>hr', function()
+        gs.reset_hunk { vim.fn.line '.', vim.fn.line 'v' }
+      end, { desc = 'reset git hunk' })
+      -- normal mode
+      map('n', '<leader>hs', gs.stage_hunk, { desc = 'git stage hunk' })
+      map('n', '<leader>hr', gs.reset_hunk, { desc = 'git reset hunk' })
+      map('n', '<leader>hS', gs.stage_buffer, { desc = 'git Stage buffer' })
+      map('n', '<leader>hu', gs.undo_stage_hunk, { desc = 'undo stage hunk' })
+      map('n', '<leader>hR', gs.reset_buffer, { desc = 'git Reset buffer' })
+      map('n', '<leader>hp', gs.preview_hunk, { desc = 'preview git hunk' })
+      map('n', '<leader>hb', function()
+        gs.blame_line { full = false }
+      end, { desc = 'git blame line' })
+      map('n', '<leader>hd', gs.diffthis, { desc = 'git diff against index' })
+      map('n', '<leader>hD', function()
+        gs.diffthis '~'
+      end, { desc = 'git diff against last commit' })
+
+      -- Toggles
+      map('n', '<leader>tb', gs.toggle_current_line_blame, { desc = 'toggle git blame line' })
+      map('n', '<leader>td', gs.toggle_deleted, { desc = 'toggle git show deleted' })
+
+      -- Text object
+      map({ 'o', 'x' }, 'ih', ':<C-U>Gitsigns select_hunk<CR>', { desc = 'select git hunk' })
+    end,
+  },
+}