Add Vietnamese translation for README.vi.md - #901

…ule-project#912)

Extends existing categories (preferring extensions over new lines):
- Performance/Upload: amule-project#898 SlotAllocation default raised.
- Networking & Discovery: wire-parser hardening list extended with
  amule-project#879/amule-project#882/amule-project#890/amule-project#886; new amuleweb security hardening bullet
  consolidating ngosang's amule-project#869-amule-project#874 triage (all landed in amule-project#875);
  amulegui list extended with amule-project#857; shared-folder watcher extended
  with amule-project#858.
- Packaging: Windows installer i18n line extended with amule-project#899.
- Internals & Refactoring: new docs-polish + code-quality bullets
  covering amule-project#851/amule-project#855/amule-project#862/amule-project#888/amule-project#900/amule-project#866/amule-project#867/amule-project#895 and amule-project#909/amule-project#910/amule-project#912.
- Translations: new pre-release final-wave bullet covering amule-project#847/amule-project#856/
  amule-project#891/amule-project#908/amule-project#860/amule-project#904/amule-project#859/amule-project#863/amule-project#861/amule-project#880/amule-project#911/amule-project#901/amule-project#902/amule-project#889/amule-project#868/amule-project#853.
- Bug Fixes & Stability: amule-project#850/amule-project#854/amule-project#878/amule-project#906.
- CI: ccache wiring (amule-project#892, amule-project#903) + CodeQL binutils-dev (amule-project#907).

Contributors footer gains mifritscher and nguyenhoangminhhieu2004-gif
(both first-time contributors).

PR index extended through amule-project#912.

Extends existing categories (preferring extensions over new lines):
- Performance/Upload: #898 SlotAllocation default raised.
- Networking & Discovery: wire-parser hardening list extended with
  #879/#882/#890/#886; new amuleweb security hardening bullet
  consolidating ngosang's #869-#874 triage (all landed in #875);
  amulegui list extended with #857; shared-folder watcher extended
  with #858.
- Packaging: Windows installer i18n line extended with #899.
- Internals & Refactoring: new docs-polish + code-quality bullets
  covering #851/#855/#862/#888/#900/#866/#867/#895 and #909/#910/#912.
- Translations: new pre-release final-wave bullet covering #847/#856/
  #891/#908/#860/#904/#859/#863/#861/#880/#911/#901/#902/#889/#868/#853.
- Bug Fixes & Stability: #850/#854/#878/#906.
- CI: ccache wiring (#892, #903) + CodeQL binutils-dev (#907).

Contributors footer gains mifritscher and nguyenhoangminhhieu2004-gif
(both first-time contributors).

PR index extended through #912.