This commit adds a new Lua file `apple-pkl.lua` to the `absolute/plugins` directory. The file contains the configuration for the plugin `apple/pkl-neovim`. The configuration includes the following:
- The plugin URL: `https://github.com/apple/pkl-neovim`
- The plugin should be loaded lazily
- The plugin should be triggered on the event "BufReadPre *.pkl"
- The plugin has a dependency on `nvim-treesitter/nvim-treesitter`
- The plugin build function installs the `pkl` language for Treesitter using the command `TSInstall! pkl`
