🌐 Sync Translations + Update README Progress Table (#3638)

### Description of Changes

This Pull Request was automatically generated to synchronize updates to
translation files and documentation. Below are the details of the
changes made:

#### **1. Synchronization of Translation Files**
- Updated translation files (`messages_*.properties`) to reflect changes
in the reference file `messages_en_GB.properties`.
- Ensured consistency and synchronization across all supported language
files.
- Highlighted any missing or incomplete translations.

#### **2. Update README.md**
- Generated the translation progress table in `README.md`.
- Added a summary of the current translation status for all supported
languages.
- Included up-to-date statistics on translation coverage.

#### **Why these changes are necessary**
- Keeps translation files aligned with the latest reference updates.
- Ensures the documentation reflects the current translation progress.

---

Auto-generated by [create-pull-request][1].

[1]: https://github.com/peter-evans/create-pull-request

Co-authored-by: stirlingbot[bot] <195170888+stirlingbot[bot]@users.noreply.github.com>

README.md

@@ -128,7 +128,7 @@ Stirling-PDF currently supports 40 languages!
 | English (English) (en_GB)                    | ![100%](https://geps.dev/progress/100) |
 | English (US) (en_US)                         | ![100%](https://geps.dev/progress/100) |
 | French (Français) (fr_FR)                    | ![82%](https://geps.dev/progress/82)   |
-| German (Deutsch) (de_DE)                     | ![89%](https://geps.dev/progress/89)   |
+| German (Deutsch) (de_DE)                     | ![99%](https://geps.dev/progress/99)   |
 | Greek (Ελληνικά) (el_GR)                     | ![80%](https://geps.dev/progress/80)   |
 | Hindi (हिंदी) (hi_IN)                          | ![80%](https://geps.dev/progress/80)   |
 | Hungarian (Magyar) (hu_HU)                   | ![87%](https://geps.dev/progress/87)   |