chore: text cleanup

src/main/resources/lessons/jwt/documentation/JWT_claim_misuse_jku.adoc

@@ -16,9 +16,9 @@ An example JKU would look like this:
 }
 ----
 
-=== Vulnerability
+=== Vulnerability: JWT claim misuse with JKU
 
-JWT claim misuse with JKU The vulnerability arises when a JWT is signed with a weak or predictable key and the server provides a JKU that points to an external location hosting the public key.
+The vulnerability arises when a JWT is signed with a weak or predictable key and the server provides a JKU that points to an external location hosting the public key.
 
 Attackers can exploit this vulnerability by crafting a JWT with malicious claims and using the `jku` to trick the server into verifying the JWT using a weak or manipulated key.
 It all depends on the library being used inside the application.
@@ -39,6 +39,7 @@ However, filtering on URLs is quite challenging to implement, and this can be by
 
 - **Successful attack**: If the server uses the weak or manipulated key to verify the JWT, the attacker gains unauthorized access or executes their intended exploit.
 
+
 === Mitigation
 
 To prevent JWT claim misuse with JKU, developers and security professionals should follow these best practices: