Updates for 2026

[pintergreg]

• users use 20% of the features #58
• additional resources #59
• Update project assignment slides #62
• Add summary to the end of the lecture presentations #64
• Extend wireframing with UI/UX #70
• Include laws of software engineering #73
• Make citations link #74
• https://github.com/iluwatar/programming-principles
• miscellaneous fixes
• apply common grading