docs: add CLI help

docs/cmd/tk_sync_source.md

@@ -0,0 +1,30 @@
+## tk sync source
+
+Synchronize source commands
+
+### Synopsis
+
+Synchronize source commands
+
+### Options
+
+```
+  -h, --help   help for source
+```
+
+### Options inherited from parent commands
+
+```
+      --components strings   list of components, accepts comma-separated values (default [source-controller,kustomize-controller])
+      --kubeconfig string    path to the kubeconfig file (default "~/.kube/config")
+      --namespace string     the namespace scope for this operation (default "gitops-system")
+      --timeout duration     timeout for this operation (default 5m0s)
+      --verbose              print generated objects
+```
+
+### SEE ALSO
+
+* [tk sync](tk_sync.md)	 - Synchronize commands
+* [tk sync source git](tk_sync_source_git.md)	 - Synchronize git source
+
+###### Auto generated by spf13/cobra on 30-Apr-2020