The English contents has changed, leading to untranslated session
outline and schedule because the msgid no longer match the original
contents. Additionally, incorrect file names are listed in the comment.
This PR follow the steps outlined in [Refreshing an Existing
Translation](https://github.com/google/comprehensive-rust/blob/main/TRANSLATIONS.md#refreshing-an-existing-translation)
to refresh the Vietnamese translation file. After the update, some
translated session outlines were no longer appropriated, so this PR also
updates all of them
The translation of *Welcome to Comprehensive Rust:
(1) Running the Course*.
I have followed the [Contributing
Guidelines](b38d429e49/CONTRIBUTING.md):
- [x] Edited by Poedit
- [x] Formatted by `dprint fmt`
- [x] Submitted to the CLA
