Organize and commit nvim configuration improvements

**Configuration Enhancements:**
- Enable Nerd Font support in init.lua
- Enhanced LSP configuration with better clangd setup
- Improved query driver paths and error handling
- Added support for more filetypes (cmake, tex, etc.)

**Plugin Management:**
- Add GitHub Copilot integration
- Remove experimental plugins (avante, completion, statusline, theme)
- Reorganize plugin imports for better structure

**Repository Maintenance:**
- Update .gitignore for better artifact handling
- Clean up unused plugin configurations
- Establish clean baseline for future development

Resolves #12

lua/custom/plugins/init.lua

@@ -3,14 +3,15 @@
 --
 -- See the kickstart.nvim README for more information
 return {
-  { import = 'custom.plugins.avante' },
   -- { import = 'custom.plugins.completion' },
+  -- { import = 'custom.plugins.theme' },
+  -- { import = 'custom.plugins.avante' },
+  { import = 'custom.plugins.copilot' },
   { import = 'custom.plugins.debug' },
   { import = 'custom.plugins.formatting' },
   { import = 'custom.plugins.git' },
   { import = 'custom.plugins.lsp' },
   { import = 'custom.plugins.nvim-tmux-navigator' },
   { import = 'custom.plugins.telescope' },
-  -- { import = 'custom.plugins.theme' },
   { import = 'custom.plugins.treesitter' },
 }