Add stuff for enhance

[djensenius]

This pull request introduces a Catppuccin Mocha themed configuration for the gh-dash GitHub dashboard and aligns related shell environment and installation scripts for improved integration and user experience. The changes include a new, detailed gh-dash config with custom sections, keybindings, and color theming, as well as updates to environment variables and install scripts to ensure consistency across CLI tools.

GitHub Dashboard and CLI Integration:

• Added a comprehensive gh-dash/config.yml with Catppuccin Mocha theming, custom PR/issue sections, keybindings for companion tools (like gh enhance, lazygit, octo.nvim, and Copilot CLI), and detailed color/icon configuration for roles and UI elements.
• Updated the install.sh script to symlink both gh-dash and gh configuration files into the user's config directories, ensuring the new theming and settings are applied automatically.

Shell Environment Enhancements:

• Set the ENHANCE_THEME environment variable in fish/conf.d/00-env.fish to catppuccin_mocha, ensuring gh enhance matches the dashboard's theme.

Copilot CLI Improvements:

• Improved the copilot Fish shell completions: clarified the --resume option to include ID prefix support and added a new --session-id option for resuming or setting session UUIDs.