Add documentation for missing flags

[straight-shoota]

Detected via #734

[netlify]

✅ Deploy Preview for crystal-book ready!

Name	Link
🔨 Latest commit	149780c
🔍 Latest deploy log	https://app.netlify.com/sites/crystal-book/deploys/65a43107ae406a000848cd4c
😎 Deploy Preview	https://deploy-preview-735--crystal-book.netlify.app/syntax_and_semantics/compile_time_flags
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[Blacksmoke16]

That script seems to have missed no_restrictions_augmenter, as mentioned in https://forum.crystal-lang.org/t/inconsistent-document-about-autocasting/6295/7

[straight-shoota]

The script only lists flags that are actually used in Crystal code via flag?. It does not cover flags that are handled by the compiler directly.

[straight-shoota]

Might be able to add that, though.