fix(nvim-cmp): Check for nil value in opts table (#1559)

* feat(nvim-cmp): fix the issue of opts.sources not being initialized at the start

* Update lua/astrocommunity/completion/nvim-cmp/init.lua

---------

Co-authored-by: Uzair Aftab <48220549+Uzaaft@users.noreply.github.com>

Author: lixiao189

lua/astrocommunity/completion/nvim-cmp/init.lua

@@ -222,7 +222,10 @@ return {
       specs = {
         {
           "hrsh7th/nvim-cmp",
-          opts = function(_, opts) table.insert(opts.sources, { name = "lazydev", group_index = 0 }) end,
+          opts = function(_, opts)
+            if not opts.sources then opts.sources = {} end
+            table.insert(opts.sources, { name = "lazydev", group_index = 0 })
+          end,
         },
       },
     },