Add installation instructions for metalctl (#200)

docs/usage/metalctl.md

@@ -1,6 +1,16 @@
 # metalctl
 
-## move
+## Installation
+
+Install the `metalctl` CLI from source without cloning the repository. Requires [Go](https://go.dev) to be installed.
+
+```bash
+go install https://github.com/ironcore-dev/metal-operator/cmd/metalctl@latest
+```
+
+## Commands
+
+### move
 
 The `metalctl move` command allows to move the metal Custom Resources, like e.g. `Endpoint`, `BMC`, `Server`, etc. from one
 cluster to another.
@@ -34,7 +44,7 @@ several limitation for this scenario, like e.g. the implementation assumes the c
 move operation, and possible race conditions happening while the cluster is upgrading, scaling up, remediating etc. has
 never been investigated nor addressed.
 
-### Pivot
+#### Pivot
 
 Pivoting is a process for moving the Custom Resources and install Custom Resource Definitions from a source cluster to
 a target cluster.
@@ -44,7 +54,7 @@ This can now be achieved with the following procedure:
 1. Use `make install` to install the metal Custom Resource Definitions into the target cluster
 2. Use `metalctl move` to move the metal Custom Resources from a source cluster to a target cluster
 
-### Dry run
+#### Dry run
 
 With `--dry-run` option you can dry-run the move action by only printing logs without taking any actual actions. Use
 `--verbose` flag to enable verbose logging.