fix: replace deprecated nerdfont icons (#1035)

Co-authored-by: Shadman <[email protected]>

Author: yujinyuz

examples/evil_lualine.lua

@@ -200,7 +200,7 @@ ins_right {
 ins_right {
   'diff',
   -- Is it me or the symbol for modified us really weird
-  symbols = { added = ' ', modified = '柳 ', removed = ' ' },
+  symbols = { added = ' ', modified = '󰝤 ', removed = ' ' },
   diff_color = {
     added = { fg = colors.green },
     modified = { fg = colors.orange },

tests/spec/lualine_spec.lua

@@ -732,7 +732,7 @@ describe('Lualine', function()
             3: lualine_a_buffers_inactive = { bg = "#3c3836", bold = true, fg = "#a89984" }
             4: lualine_c_normal = { bg = "#3c3836", fg = "#a89984" }
         }
-        |{1:  a.txt }
+        |{1: 󰈙 a.txt }
         {2:}
         {3: ... }
         {4:                                                                                                         }|