Update book and templates with feature freeze#14456

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blyxyas wants to merge 7 commits intorust-lang:masterfrom

blyxyas:feature-freeze

Commits on Mar 21, 2025

Commits on Mar 23, 2025

Move back date 6 weeks
blyxyas
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Commits on Apr 7, 2025

Commits on May 28, 2025