Create CLI docs in Master (#601)

content/master/cli/_index.md

@@ -0,0 +1,64 @@
+---
+weight: 400
+title: Crossplane CLI
+description: "Documentation for the Crossplane command-line interface"
+---
+
+The Crossplane CLI helps simplify some development and administration aspects of
+Crossplane.
+
+The Crossplane CLI includes:
+* tools to build, install, update and push Crossplane Packages
+* standalone Composition Function testing and rendering without the need to access a Kubernetes cluster running Crossplane
+* troubleshoot Crossplane Compositions, Composite Resources and Managed Resources
+
+## Installing the CLI
+
+The Crossplane CLI is a single standalone binary with no external dependencies.
+
+{{<hint "note" >}}
+Install the Crossplane CLI on a user's computer. 
+
+Most Crossplane CLI commands are independent of Kubernetes and 
+don't require access to a Crossplane pod.
+{{< /hint >}} 
+
+To download the latest version for your CPU architecture with the Crossplane
+install script.
+
+```shell
+curl -sL "https://raw.githubusercontent.com/crossplane/crossplane/master/install.sh" | sh
+```
+
+[The script](https://raw.githubusercontent.com/crossplane/crossplane/master/install.sh)
+detects your CPU architecture and downloads the latest stable release.
+
+{{<expand "Manually install the Crossplane CLI" >}}
+
+If you don't want to run shell script you can manually download a binary from 
+the Crossplane releases repository at 
+https://releases.crossplane.io/stable/current/bin
+
+{{<hint "important" >}}
+<!-- vale write-good.Passive = NO -->
+The CLI is named `crank` in the release repository. Download this file. 
+<!-- vale write-good.Passive = YES -->
+
+The `crossplane` binary is the Kubernetes Crossplane pod image.
+{{< /hint >}}
+
+Move the binary to a location in your `$PATH`, for example `/usr/local/bin`.
+{{< /expand >}}
+
+### Download other CLI versions
+
+Download different Crossplane CLI versions or different release branches with
+the `XP_CHANNEL` and `XP_VERSION` environmental variables. 
+
+By default the CLI installs from the `XP_CHANNEL` named `stable` and the 
+`XP_VERSION` of `current`, matching the most recent stable release.
+
+For example, to install CLI version `v1.14.0` add `XP_VERSION=v1.14.0` to the 
+download script curl command:  
+
+`curl -sL "https://raw.githubusercontent.com/crossplane/crossplane/master/install.sh" | XP_VERSION=v1.14.0 sh`