Improve README; check-ssh
Monitor SSHD status.
-## Usage
+## Synopsis
+```
+check-ssh -w 1 -c 3
+```
+
+## Installation
+
+First, build this program.
```
-$ check-ssh -w 1 -c 3
+go get github.com/mackerelio/go-check-plugins
+cd $(go env GOPATH)/src/github.com/mackerelio/go-check-plugins/check-ssh
+go install
+```
+
+Or you can use this program by installing the official Mackerel package. See [Using the official check plugin pack for check monitoring - Mackerel Docs](https://mackerel.io/docs/entry/howto/mackerel-check-plugins).
+
+Next, you can execute this program :-)
+
+```
+check-ssh -w 1 -c 3
```
-## Setting
+
+## Setting for mackerel-agent
+
+If there are no problems in the execution result, add s setting in mackerel-agent.conf .
```
-[plugin.checks.ssh-to-foo]
-command = "/path/to/check-ssh -H foo.local -u foo -i /path/to/foo_id_rsa -t 10 -w 1 -c 10"
+[plugin.checks.check-ssh-sample]
+command = ["check-ssh", "-w", "1", "-c", "3"]
```
+
+## Usage
+### Options
+
+```
+ -H, --hostname= Host name or IP Address (default: localhost)
+ -P, --port= Port number (default: 22)
+ -t, --timeout= Seconds before connection times out (default: 30)
+ -w, --warning= Response time to result in warning status (seconds)
+ -c, --critical= Response time to result in critical status (seconds)
+ -u, --user= Login user name [$USER]
+ -p, --password= Login password [$LOGIN_PASSWORD]
+ -i, --identity= Identity file (ssh private key)
+ --passphrase= Identity passphrase [$CHECK_SSH_IDENTITY_PASSPHRASE]
+```
+
+## For more information
+
+Please execute `check-ssh -h` and you can get command line options.
