Add independent font sizes and font override options for overlay achievements

[dasafe]

Description:
Add independent font size settings and font override options for overlay elements.

How It Works
Before: The overlay used a single font with one font size for all text (FPS counter, achievement title, achievement description).
After: Each text element can have its own independent font size and optional font override.

New Settings

• Font_Size_FPS - Font size for FPS counter
• Font_Size_Achievement_Title - Font size for achievement title
• Font_Size_Achievement_Description - Font size for achievement description
• Font_Override_Achievement_Title - Custom TTF font file for achievement title
• Font_Override_Achievement_Description - Custom TTF font file for achievement description
• Font_Achievement_Title_Bold - Make achievement title bold (0/1)

How It Works

1. Settings parser reads the new font size and override settings from config
2. create_fonts() creates separate font instances for each size
3. render_stats() and notification rendering use the appropriate font for each element
4. If a custom font override is specified, it loads that TTF instead of the default

Users can now customize the overlay to match their preferences - smaller FPS text, different fonts for achievements, etc.

Changes

• Add independent font sizes for FPS (font_size_fps), achievement title (font_size_ach_title), and achievement description (font_size_ach_desc)
• Add font override options for achievement title and description
• Add Font_Achievement_Title_Bold setting
• Update create_fonts() and render_stats() to support independent fonts
• Add Font_Override_Achievement_Title, Font_Override_Achievement_Description, and Font_Achievement_Title_Bold to overlay example config