Update info on available SSDP data (home-assistant#647)

docs/creating_integration_manifest.md

@@ -129,7 +129,7 @@ Certain zeroconf types are very generic (i.e., `_printer._tcp.local.`, `_axis-vi
 
 ## SSDP
 
-If your integration supports discovery via [SSDP](https://en.wikipedia.org/wiki/Simple_Service_Discovery_Protocol), you can add the type to your manifest. If the user has the `ssdp` integration loaded, it will load the `ssdp` step of your integration's config flow when it is discovered. We support SSDP discovery by ST, and all data in UPnP device description. The manifest value is a list of matcher dictionaries, your integration is discovered if all items of any of the specified matchers are found in the SSDP/UPnP data. It's up to your config flow to filter out duplicates.
+If your integration supports discovery via [SSDP](https://en.wikipedia.org/wiki/Simple_Service_Discovery_Protocol), you can add the type to your manifest. If the user has the `ssdp` integration loaded, it will load the `ssdp` step of your integration's config flow when it is discovered. We support SSDP discovery by the SSDP ST, USN, EXT, and Server headers (header names in lowercase), as well as data in [UPnP device description](https://openconnectivity.org/developer/specifications/upnp-resources/upnp/basic-device-v1-0/). The manifest value is a list of matcher dictionaries, your integration is discovered if all items of any of the specified matchers are found in the SSDP/UPnP data. It's up to your config flow to filter out duplicates.
 
 The following example has one matcher consisting of three items, all of which must match for discovery to happen by this config.