🌐 Sync Translations + Update README Progress Table (#3349)

### 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>

src/main/resources/messages_bg_BG.properties

@@ -10,6 +10,9 @@ multiPdfPrompt=Изберете PDF (2+)
 multiPdfDropPrompt=Изберете (или плъзнете и пуснете) всички PDF файлове, от които се нуждаете
 imgPrompt=Изберете изображение(я)
 genericSubmit=Подайте
+uploadLimit=Maximum file size:
+uploadLimitExceededSingular=is too large. Maximum allowed size is
+uploadLimitExceededPlural=are too large. Maximum allowed size is
 processTimeWarning=Предупреждение: Този процес може да отнеме до минута в зависимост от размера на файла
 pageOrderPrompt=Персонализиран ред на страниците (Въведете разделен със запетаи списък с номера на страници или функции като 2n+1):
 pageSelectionPrompt=Персонализиран избор на страница (Въведете списък с номера на страници 1,5,6, разделени със запетая, или функции като 2n+1) :