update SSH note

ssh/README.md

@@ -20,6 +20,8 @@ To connect to a server, run:
 
     ssh -p port user@server-address
 
+`port` for default is `22`
+
 ### Copy SSH key
 
 1. `sudo apt-get install xclip` or `sudo pacman -S xclip`
@@ -34,9 +36,11 @@ The client can be configured to store common options and hosts. All options can
 
 # host-specific options
 Host myserver
-    HostName server-address
-    Port     port
-
+    HostName ssh.heckyel.ga
+    IdentityFile ~/.ssh/id_rsa
+    user Snowden
+    Port 22
+    ServerAliveInterval 5
 ```
 
 With such a configuration, the following commands are equivalent