Maya Sketchfab Exporter - v2.6

• Adds Apache 2.0 License
• Updates to Sketchfab API v3
• Fixes long vs int error in Maya 2022
• Cleans unused imports
• Cleans whitespace
• Cleans string formatting inconsistencies
• Removes polling for processing status
• Adds check to fix failing silently on missing API Token
• Adds link to find API Token
• Updates outdated help links
• Removes exporting an unused screenshot