doc: add missing parenthesis in TLSSocket section

PR-URL: #44512
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

doc/api/tls.md

@@ -807,7 +807,7 @@ negotiation.
 Instances of `tls.TLSSocket` implement the duplex [Stream][] interface.
 
 Methods that return TLS connection metadata (e.g.
-[`tls.TLSSocket.getPeerCertificate()`][] will only return data while the
+[`tls.TLSSocket.getPeerCertificate()`][]) will only return data while the
 connection is open.
 
 ### `new tls.TLSSocket(socket[, options])`