Quote2Image V0.5

• Added new convert function argument watermark_text: Allows users to add a watermark to the bottom right corner of the image with a custom font size.
• Added default font_size_author for author: If not specified, it will default to quote font size.
• Fixed bug with ImgObject class: Brightness and blur values were not being applied properly.
• Improved documentation: Updated usage examples and added more detailed explanations of the new features.