content: Link cloud-hypervisor support status

Add entry in `SUMMARY.md` to link cloud-hyperviosr riscv64 suppport
status page.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

Author: RuoqingHe

src/SUMMARY.md

@@ -5,3 +5,8 @@
 - [Firecraker](<>)
   - [Markdown Files](repo-management/firecracker/markdown.md)
   - [Rust Files](repo-management/firecracker/rustfmt.md)
+
+# Virtualization Observation
+
+- [Cloud-Hypervisor](<>)
+  - [RISC-V Support](virtualization/cloud-hypervisor/riscv64-architecture-support.md)