Add airshipctl phase run

Commands execution logic will be added when executors are implemented

Change-Id: I78ef95a858117d0c6d407289955228b6ba1a3d5e

docs/source/cli/airshipctl_phase_run.md

@@ -0,0 +1,40 @@
+## airshipctl phase run
+
+Run phase
+
+### Synopsis
+
+Run specific life-cycle phase such as ephemeral-control-plane, target-initinfra etc...
+
+```
+airshipctl phase run PHASE_NAME [flags]
+```
+
+### Examples
+
+```
+
+# Run initinfra phase
+airshipctl phase run ephemeral-control-plane
+
+```
+
+### Options
+
+```
+      --dry-run   simulate phase execution
+  -h, --help      help for run
+```
+
+### Options inherited from parent commands
+
+```
+      --airshipconf string   Path to file for airshipctl configuration. (default "$HOME/.airship/config")
+      --debug                enable verbose output
+      --kubeconfig string    Path to kubeconfig associated with airshipctl configuration. (default "$HOME/.airship/kubeconfig")
+```
+
+### SEE ALSO
+
+* [airshipctl phase](airshipctl_phase.md)	 - Manage phases
+