Make the signature of templates cleaner.

[kaj]

This is a breaking change.

I hope to enable #88 with this signature change, but that doesn't really seem to happen with the change currently in this PR. So I might try a slightly different signature.

[OskarPersson]

FYI this also fixes the following Clippy error 🎉

warning: this expression borrows a reference (`&mut W`) that is immediately dereferenced by the compiler
  --> /path/to/file_html.rs:79:15
   |
79 | foo(&mut _ructe_out_)?;
   |     ^^^^^^^^^^^^^^^^ help: change this to: `_ructe_out_`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

$ cargo clippy --version
clippy 0.1.58 (02072b4 2022-01-11)

[vbrandl]

Any news on when/if this will be merged? Or a way to suppress the clippy lint mentioned by @OskarPersson ?

[kaj]

Yes, no ... I'm kind of stuck in #88 , so I haven't decided on this one either. Maybe I should just do something that seems ok here, get a release out and worry about #88 later.

[vbrandl]

Would be cool to have this fixed, so CI pipelines with clippy will pass again :)