fix: update PKGBUILD URL to mohamad/doh-forwarder repo

DEVELOP.md

@@ -78,6 +78,12 @@ Before pushing, verify:
 - [ ] No `unwrap()` outside of tests
 - [ ] Config values are externalized (not hardcoded)
 
+## References
+
+- [Intra Comparison](docs/intra-comparison.md) — Architectural comparison
+  with Jigsaw's Intra, explaining why DNS forwarding alone can't bypass
+  censorship and what's needed (TLS splitting, TUN interception, etc.)
+
 ## Milestone Tracking
 
 See [docs/plan.md](docs/plan.md) for the full project plan and milestone checklist.