Fixed issue #71, added config subcommand and function to set a git remote

[x0f5c3]

#71 Fixed by first converting the Config value into a toml Value then serializing it.
As suggested in Issue #142 - toml-rs
Unfortunately the solution presented later and merged into master doesn't apply to this so the first workaround had to be used.
Also added a way to create a new config and configure the repo including changing the path from the default using dialoguer MultiSelect and Select prompts and by adding a new subcommand with two command line switches. To allow setting a new repo path and creating one locally I also had to add a function to set a git remote for the repository.
Code has been formatted with RustFmt and checked with clippy.
If there's anything that needs to be fixed or changed for this to work then please let me know.

[tversteeg]

Thanks a lot, this is looking good! Could you add a small section of how the new flag works at the bottom of README.md? If you do that I'll merge it :)

[x0f5c3]

Thanks for merging, I think there is more stuff I could add so I'll probably make more requests in the future since I really like the project.

[tversteeg]

Thanks for the kind words, looking forward to seeing your pull requests!