ncat: add -k option (#2043)

pages/linux/ncat.md

@@ -4,8 +4,12 @@
 
 - Listen for input on the specified port and write it to the specified file:
 
-`ncat -l {{port}} > {{/path/to/file}}`
+`ncat -l {{port}} > {{path/to/file}}`
+
+- Accept multiple connections and keep ncat open after they have been closed:
+
+`ncat -lk {{port}}`
 
 - Write output of specified file to the specified host on the specified port:
 
-`ncat {{address}} {{port}} < {{/path/to/file}}`
+`ncat {{address}} {{port}} < {{path/to/file}}`