Add CLI config overrides

Adds ability to override all boolean, integer & string liftoffrc config options with CLI arguments. Fixes #124.

```
--[no-]cp
--[no-]git
--[no-]warnings
--[no-]todo-scripts
--[no-]static-analyzer
--indentation_level N ... alias -t
--project_name [PROJECT_NAME] ... alias -n
--company [COMPANY] ... alias -c
--author [AUTHOR] ... alias -a
--prefix [PREFIX] ... alias -p
--identifier [IDENTIFIER] ... alias -i
```