docs: readme feature & capabilities updates

- Mention experimental vsock support.
- Link the jailer to its docs.

Signed-off-by: Radu Weiss <[email protected]>

Author: raduweiss

README.md

@@ -90,15 +90,18 @@ The **API endpoint** can be used to:
 - Configure the logging and metric system.
 - `[BETA]` Configure the data tree of the guest-facing metadata service. The
   service is only available to the guest if this resource is configured.
+- `[EXPERIMENTAL]` Add one or more [vsock sockets](docs/experimental-vsock.md)
+  to the microVM.
 - Start the microVM using a given kernel image, root file system, and boot
   arguments.
 - Stop the microVM.
 
 **Built-in Capabilities**:
 
 - Demand fault paging and CPU oversubscription enabled by default.
-- Jailer process for starting Firecracker in production scenarios; applies a
-  cgroup/namespace/seccomp rule isolation barrier and then drops privileges. 
+- [Jailer](docs/jailer.md) process for starting Firecracker in production
+  scenarios; applies a cgroup/namespace/seccomp rule isolation barrier and then
+  drops privileges. 
 
 ## Performance