provide "drush help" documentation

there is no hostmaster command.

provision-backup      Generate a back up for the site.                                                                                                   
 provision-clone       Clone a site between platforms.                                                                                                    
 provision-delete      Delete a site.                                                                                                                     
 provision-deploy      Deploy an existing backup to a new url.                                                                                            
 provision-disable     Disable a site.                                                                                                                    
 provision-enable      Enable a disabled site.                                                                                                            
 provision-import      Turn an already running site into a provisioned site.                                                                              
 provision-install     Provision a new site using the provided data.                                                                                      
 provision-lock        Lock a platform from having any other sites provisioned on it.                                                                     
 provision-login_rese  Generate a one-time login reset URL.                                                                                               
 t                                                                                                                                                        
 provision-migrate     Migrate a site between platforms.                                                                                                  
 provision-rename      Rename a site.                                                                                                                     
 provision-restore     Restore the site to a previous backup. This will also generate a backup of the site as it was.                                     
 provision-save        Save Drush alias                                                                                                                   
 provision-unlock      Unlock a platform so that sites can be provisioned on it.                                                                          
 provision-verify      Verify that the provisioning framework is correctly installed.                               

all the commands have help.

Your git announcement at http://developmentseed.org/blog/2009/nov/22/aegir-hosting-system-moves-git cites 'drush hostmaster ...' twice, possibly causing one to think there is a hostmaster command.