docs: Add serialization-based schema generation docs (#197)

- Added documentation for runtime JSON schema generation using
`@Serializable` classes.
- Included a new link to "Serialization-Based Schema Generation" in
README.
- Updated docs Gradle configuration
- Enhanced Makefile and AGENTS.md with updated Knit commands and
instructions.


### Pre-Submission Checklist

- [ ] **Self-reviewed** my own code
- [ ] **Tests added/updated** and passing locally
- [x] **Documentation updated** (if needed: README, code comments, etc.)
- [ ] **Focused PR**: Single concern, no unrelated changes or "drive-by"
fixes
- [ ] **Breaking changes documented** (if applicable)
- [ ] **No debug code**: Removed commented-out code and debug statements

---

## Reviewer Guidelines

### What should reviewers focus on?
<!-- Optional: Highlight specific areas needing extra attention -->

### Review Philosophy
Following Google's principle: **Approve if this PR improves the
codebase**, even if it's not perfect.

- [The Standard of Code
Review](https://github.com/google/eng-practices/blob/master/review/reviewer/standard.md)
- [What to look
for](https://github.com/google/eng-practices/blob/master/review/reviewer/looking-for.md)

**For Reviewers:**
- [ ] Does this improve the codebase overall?
- [ ] Are there any critical issues that block approval?
- [ ] Can remaining improvements be addressed in follow-up PRs?

---

## Additional Notes

Explains Question #193

Author: kpavlov

AGENTS.md

@@ -208,6 +208,7 @@ Each module must have a `Module.md` file at the module root for Dokka-generated
 - Build all modules: `./gradlew build`
 - Run all tests: `./gradlew test`
 - KSP integration tests: `make integration-test`
+- Verify knit examples compile: `make knit`
 
 ## When to ask for help
 

Makefile

@@ -27,13 +27,14 @@ scan:
 apidocs:
 	@echo "📚 Generating API documentation..."
 	@rm -rf docs/public/apidocs && \
-	./gradlew clean :docs:dokkaGenerate
+	@./gradlew clean :docs:dokkaGenerate
 	@echo "✅ API docs generated!"
 
 .PHONY: knit
 knit:
 	@echo "🪡🧶 Running Knit check ..."
-	./gradlew :docs:clean knit knitCheck :docs:testClasses --no-configuration-cache
+	@./gradlew :docs:clean knit knitCheck :docs:test --no-configuration-cache
+	@./gradlew :docs:test
 	@echo "✅ Knit check completed!"
 
 .PHONY: clean