Add note for same command

Author: tats-u

xml/en/docs/http/ngx_http_auth_basic_module.xml

@@ -97,6 +97,9 @@ The following password types are supported:
 encrypted with the <c-func>crypt</c-func> function; can be generated using
 the “<command>htpasswd</command>” utility from the Apache HTTP Server
 distribution or the “<command>mkpasswd</command>” or “<command>openssl passwd</command>” command;
+<note>
+“<command>mkpasswd</command” can be installed by “<command>apt install whois</command>” in Ubuntu / Debian or “<command>dnf install mkpasswd</command>” in RHEL 9+. The command with the same name, “<command>mkpasswd</command>”, which is included in the “expect” package in RHEL8 and earlier, is a different command. It was renamed to “<command>mkpasswd-expect</command>” in RHEL 9.
+</note>
 </listitem>
 
 <listitem>