Support time components in `date_format`

[hulr]

Thank you very much for creating IWE! It's exactly the tool I was looking for to improve my workflow.

I would like to use the minute (%M) and hour (%H) number in date_format. The config would look something like this:

[library]
path = ""
date_format = "%Y%m%d%M%H"

[templates.default]
key_template = "{{today}} {{title}}"
document_template = "# {{today}} {{title}}"

Currently, when trying to create a new document with iwe new and the config from above I get the following error:

$ iwe --version
iwe 0.0.60

$ RUST_BACKTRACE=full iwe new "test"

thread 'main' (8290) panicked at /build/rustc-1.93.0-src/library/alloc/src/string.rs:2889:14:
a Display implementation returned an error unexpectedly: Error
stack backtrace:
   0:     0x5562a431ffab - <std::sys::backtrace::BacktraceLock::print::DisplayBacktrace as core::fmt::Display>::fmt::h4abbbc3d9ecfa86c
   1:     0x5562a433c507 - core::fmt::write::he00acd824749ac8b
   2:     0x5562a42e0b42 - std::io::default_write_fmt::h43bad14283851991
   3:     0x5562a43197b2 - std::sys::backtrace::BacktraceLock::print::h79d51edf656c8655
   4:     0x5562a42e347c - std::panicking::default_hook::{{closure}}::hfdec67f3f6a8e696
   5:     0x5562a42e3315 - std::panicking::default_hook::h8ddbbb7d400ff4fb
   6:     0x5562a42e35fb - std::panicking::panic_with_hook::ha4edca3cf4c438c6
   7:     0x5562a43199a8 - std::panicking::panic_handler::{{closure}}::h114a630d885f2c13
   8:     0x5562a43198b9 - std::sys::backtrace::__rust_end_short_backtrace::hf6231de488bca95f
   9:     0x5562a42e035d - __rustc[881eff9798cad629]::rust_begin_unwind
  10:     0x5562a3f7063c - core::panicking::panic_fmt::h7509f5fc1f52ade1
  11:     0x5562a3f70742 - core::result::unwrap_failed::h4811fcb6dcdb23ec
  12:     0x5562a3fb68d8 - iwe::new::DocumentCreator::create::hb69c6c1ed1c53f9a
  13:     0x5562a3f7c9ce - iwe::main::hb53d3b5374955c2d
  14:     0x5562a3fa2ce6 - std::sys::backtrace::__rust_begin_short_backtrace::h31f2e4557eb15318
  15:     0x5562a3f9e42c - std::rt::lang_start::{{closure}}::h60d4ca20d2ad014e
  16:     0x5562a42fa4f6 - std::rt::lang_start_internal::h4a4e50345e9944f8
  17:     0x5562a3f8695d - main
  18:     0x7fe24c42b285 - __libc_start_call_main
  19:     0x7fe24c42b338 - __libc_start_main_alias_2
  20:     0x5562a3f70775 - _start
  21:                0x0 - <unknown>

I think this is because IWE is using NaiveDate which does not have the time components.

iwe/crates/iwe/src/new.rs

Lines 100 to 102 in c891e7c

	let date = Local::now().date_naive();
	let key_today = date.format(&key_date_format).to_string();
	let markdown_today = date.format(&markdown_date_format).to_string();

Would it be possible to support the time components (hour and minute number) in date_format for both library and markdown settings (f.e. using NaiveDateTime)?