feat(plugins): add example of using astrocommunity repo

plugins/community.lua

@@ -0,0 +1,9 @@
+return {
+  -- Add the community repository of plugin specifications
+  "AstroNvim/astrocommunity",
+  -- example of imporing a plugin, comment out to use it or add your own
+  -- available plugins can be found at https://github.com/AstroNvim/astrocommunity
+
+  -- { import = "astrocommunity.colorscheme.catppuccin" },
+  -- { import = "astrocommunity.completion.copilot-lua-cmp" },
+}