Update config in readme

[tjex]

Options to trace_lsp were not up to date, as confirmed by expectations stated in error message:

Failed to run `config` for copilot.lua local

...jex/.local/src/copilot.lua/lua/copilot/config/logger.lua:40: trace_lsp: expected off, verbose or debug, got messages

...

[tjex]

cleaned up the commit history.