Add Syslog section (#15)

* Update usage-settings.md

* Update usage-report.md

* Update usage-report.md

Author: knqyf263

docs/usage-report.md

@@ -24,6 +24,7 @@ report:
                 [-ignore-unfixed]
                 [-to-email]
                 [-to-slack]
+                [-to-syslog]
                 [-to-localfile]
                 [-to-s3]
                 [-to-azure-blob]
@@ -127,6 +128,9 @@ report:
         Write report to S3 (bucket/dir/yyyyMMdd_HHmm/servername.json/xml/txt)
   -to-slack
         Send report via Slack
+  -to-syslog
+        Send report via Syslog
+
 ```
 
 ## How to read a report

docs/usage-settings.md

@@ -64,6 +64,34 @@ sidebar_label: Settings
     subjectPrefix = "[vuls]"
     ```
 
+- Syslog section
+    ```
+    [syslog]
+    protocol    = "tcp"
+    host        = "localhost"
+    port        = "514"
+    tag         = "vuls"
+    facility    = "local0"
+    severity    = "alert"
+    verbose     = false
+    ```
+    
+    - protocol : transfer protocol (default: empty)
+      - `tcp` or `udp` or empty  
+         If protocol is empty, vuls will connect to the local syslog server.
+    - host : syslog target host 
+        - domain name or IP address
+    - port : syslog target port (default: 514) 
+    - tag : syslog tag
+    - facility : syslog facility (default: `auth`)  
+        - kern, user, mail, daemon, etc.
+    - severity : syslog severity (default: `info`) 
+        - emerg, alert, crit, etc.
+    - verbose : verbose mode  (default: false)
+        - CVE detail, etc.
+    
+
+
 - Default section
     ```
     [default]