Make the template pass cargo clippy by resolving warnings

[andypymont]

Resolve the cargo clippy warnings in the template so that new projects created from the template will only show warnings on code added by the user.

All of the errors are clippy::uninlined_format_args

[fspoettel]

Thanks for taking the time! 👍

Cool to see that stable clippy lints for this now.

[andypymont]

No problem!

Any interest in making it pass clippy::pedantic too? I can work on a PR for those warnings if so.

[fspoettel]

I ran it over the code and think most of these lints, especially the documentation / panic related ones, are not too relevant for us and can be ignored.

There are some that we could adopt:

• clippy::single-match-else (which is a recent addition to Rust)
• clippy::if-not-else

I would accept a PR for those, but can also tackle it at some point before december this year.