Docs: Removing escape character

The escape character `\` doesn't work and should be removed from the documentation.

Closes #8029

docs/reference/cat/nodes.asciidoc

@@ -67,7 +67,7 @@ mode (`v`). The header name will match the supplied value (e.g.,
 
 ["source","sh",subs="attributes,callouts"]
 --------------------------------------------------
-% curl 192.168.56.10:9200/_cat/nodes?v\&h=id,ip,port,v,m
+% curl 192.168.56.10:9200/_cat/nodes?v&h=id,ip,port,v,m
 id   ip            port version m
 pLSN 192.168.56.30 9300 {version}   m
 k0zy 192.168.56.10 9300 {version}   m