docs(cli): add page for the cli

docs/sources/administration/cli.md

++++
+title = "Grafana CLI"
+description = "Guide to using grafana-cli"
+keywords = ["grafana", "cli", "grafana-cli", "command line interface"]
+type = "docs"
+[menu.docs]
+parent = "admin"
+weight = 8
++++
+
+# Grafana CLI
+
+Grafana cli is a small executable that is bundled with grafana server and is suppose to be executed on the same machine as grafana runs. 
+
+## Plugins
+
+The CLI helps you install, upgrade and manage your plugins on the same machine it CLI is running. You can find more information about how to install and manage your plugins at the [plugin page] ({{< relref "/installation.md" >}})
+
+## Admin
+
+> This feature is only available in grafana 4.1 and above.
+
+To show all admin commands:
+`grafana-cli admin`
+
+### Reset admin password
+
+You can reset the password for the admin user using the CLI.
+
+`grafana-cli admin reset-admin-password ...`