feat: add plugins, enable relative numbers

add barbar, git-blame and nvim-web-devicons plugins. enable both absolute and relative line numbers

lua/custom/plugins/git-blame.lua

@@ -0,0 +1,10 @@
+return {
+  'f-person/git-blame.nvim',
+  event = 'VeryLazy',
+  opts = {
+    enabled = true,
+    message_template = ' <author>, <date> • <summary>',
+    date_format = '%d/%m/%y %H:%M',
+    virtual_text_column = 1,
+  },
+}