doc: update install openresty

Nginx/install-openresty.md

@@ -28,5 +28,21 @@ openresty -v
 openresty
 
 # kill 
-kill -9 {openresty的进程号}
+openresty -s quit
+
+# cmd list
+nginx version: openresty/1.19.3.1
+Usage: nginx [-?hvVtTq] [-s signal] [-c filename] [-p prefix] [-g directives]
+
+Options:
+  -?,-h         : this help
+  -v            : show version and exit
+  -V            : show version and configure options then exit
+  -t            : test configuration and exit
+  -T            : test configuration, dump it and exit
+  -q            : suppress non-error messages during configuration testing
+  -s signal     : send signal to a master process: stop, quit, reopen, reload
+  -p prefix     : set prefix path (default: /usr/local/openresty/nginx/)
+  -c filename   : set configuration file (default: conf/nginx.conf)
+  -g directives : set global directives out of configuration file
 ```