fix: README link markdown (#174)

Signed-off-by: Robert DeSimone <[email protected]>

README.md

@@ -31,7 +31,7 @@ A large portion of personal information now also moves through connected systems
 
 Ahead-of-time coordination is often a barrier to development in many projects. Flexibility to define specialized authorization semantics for resources and the ability to integrate with external systems trustlessly are essential as the number of autonomous, specialized, and coordinating applications increases.
 
-Many high-value applications run in hostile environments. In recognition of this, many vendors now include public key functionality, such as [non-extractable keys in browsers][browser api crypto key], [certificate systems for external keys][fido], and [secure hardware enclave]s in widespread consumer devices.
+Many high-value applications run in hostile environments. In recognition of this, many vendors now include public key functionality, such as [non-extractable keys in browsers][browser api crypto key], [certificate systems for external keys][fido], and [secure hardware enclaves] in widespread consumer devices.
 
 Two related models that work exceptionally well in the above context are Simple Public Key Infrastructure ([SPKI][spki rfc]) and object capabilities ([OCAP]). Since offline operation and self-verifiability are two requirements, UCAN adopts an approach closely related to SPKI. UCANs follow the "capabilities as certificates" model, with extensions for revocation and stateful capabilities.