Update BETA-1.0.2

Changelog v1.0.2

Added

• Added an Undo-Button
• Added a Redo-Button
• Added Zoom function to the writing area

Changes

• Switched Textbox for future updates
• Enabled standard spellchecking
• Bottom bar separated from writing area
• Decreased size for writing area

Fixes

• 'Window State' and 'Library Size' Settings shared their option buttons
• Background color for some buttons didn't change when the theme is changed