Porting-Primers/src/detailed-primers/README.md

Detailed Primers

These chapters preserve the upstream primer content step by step so the direct guide does not lose version-specific detail.

Read them in order:

• 1.21.1 -> 1.21.2/3
• 1.21.2/3 -> 1.21.4
• 1.21.4 -> 1.21.5
• 1.21.5 -> 1.21.6
• 1.21.6 -> 1.21.7
• 1.21.7 -> 1.21.8
• 1.21.8 -> 1.21.9
• 1.21.9 -> 1.21.10
• 1.21.10 -> 1.21.11
• 1.21.11 -> 26.1