Add translation review, glossary, and quality guidelines to docs

[mr-raj12]

Follows up on #57 with additional documentation for the translation workflow
introduced in borgbase/vorta#2395.

Specifically, this adds documentation for the /translate review command
(added in borgbase/vorta@e3f24a8) which was not yet available when #57 was merged.

Changes:

• Document /translate review <lang> command (quality-checks glossary compliance,
  consistency, style, and technical validation)
• Add per-language glossaries section explaining .claude/skills/translate/glossaries/<lang>.md
• Add glossary of common terms table (11 terms matching SKILL.md)
• Add translation quality guidelines (DO/DON'T for placeholders, XML escaping,
  keyboard shortcuts, technical terms)
• Add workflow example showing the full translate → review → compile cycle
• Fix step order in "Adding a New Language" (glossary creation before translation)
• Expand from 6 to 8 steps to include review and glossary creation