Release 0.5.1

Changelog

• updated dependencies
• application now always default to light theme and does not follow system preferences (this is slightly annoying but it's required while the theme changer is fixed, right now the theme changer does not work if your default theme is dark and the application automatically sets a dark theme)
• updated quizlet instructions
• fixed bug #2 that prevented the creation of flashcards when a word is repeated more than once