The doc links for parameter and error structs in the reqwest-trait template were copied over from the reqwest template, but they are not valid as-is, as these functions are now part of a trait and not standalone functions. This means for them to work correctly in IDEs and docs you need to qualify them with the trait name.

For example, VSCode, shows the link with a different color and displays a preview of the function, plus clicking on the name would navigate to the function.
With this change:

Without this change:

I've also removed the trailing whitespace from the template file, let me know if you prefer that to be reverted and split into a separate PR.

Tagging openapi-generator Rust committee, like the checklist mentions: @frol @farcaller @richardwhiuk @paladinzh @jacob-pro

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

  (For Windows users, please run the script in WSL)
  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
  IMPORTANT: Do NOT purge/delete any folders/files (e.g. tests) when regenerating the samples as manually written tests may be removed.
• File the PR against the correct branch: master (upcoming 7.x.0 minor release - breaking changes with fallbacks), 8.0.x (breaking changes without fallbacks)
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.