My rationale is that setting something up to use topiary-nushell should not require remembering where you downloaded it to

Changes to make

1. Rename wrapper script from format.nu to something like format-nu or topiary-nushell
   a. Note the lack of .nu extension
2. Move the renamed wrapper to a bin folder
   a. Adjust the wrapper as necessary
3. Edit the wrapper to print a helpful message if topiary is not installed.
4. Add a .bat file with the same name alongside the wrapper with the contents nu --stdin <script-name>
   a. This allows the script to run correctly on Windows, as the shebang would not be respected
   b. I have not tested this, as I no longer use Windows
5. Update documentation to recommend putting the bin folder on your PATH, and remove references to the specific topiary-nushell path.