Feature Request: Show parse error messages

[RigoLigoRLC]

Parse error of YAML files may be inevident. I'm using this library for the first time and it threw an error stating

error: proc macro panicked
  --> src/main.rs:11:1
   |
11 | rust_i18n::i18n!("locales", fallback = "en");
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: message: Parse file `P:\prj\rust\[project]\locales\app.yml` failed

without any reasons. I had to pull this library locally and patch crates/support/src/lib.rs:L108-L109

        let trs = parse_file(&content, ext, locale)
            .unwrap_or_else(|e| panic!("Parse file `{}` failed, reason: {}", entry.display(), e));

to see whatever is wrong (RustRover didn't give me error messages on my YAML file, I can't be sure what's wrong):

error: proc macro panicked
  --> src/main.rs:11:1
   |
11 | rust_i18n::i18n!("locales", fallback = "en");
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: message: Parse file `P:\prj\rust\mcentitycleaner\locales\app.yml` failed, reason: Invalid YAML format, did not find expected key at line 12 column 11, while parsing a block mapping at line 12 column 3