These are not needed in the new world where we only submit a single time
entry at a time and entry parameters are filled in on the command line.

My guess is we'll likely have some sort of generator in the future to
create the initial `config.toml` file, but that won't contain any
logic-based data. My guess is we'll probably be able to just stick it in
a template string right inside a *.go file.

A function to generate a weekly time sheet.

Add a new `defaults` key to the config.yml file. Looks like this:

    defaults:
      client:
      project:
      module:
      task:
      work_type:
      time:
      billable:

This will be used to fill in default values when a timesheet is
generated.