Add spaceapid update endpoint

Configure the device name and the update endpoint to report open status to spaceapid.

README.md

@@ -18,6 +18,8 @@ All configuration is handled through environment variables.
 | `IDINVITE_OIDC_SCOPE`               | `["openid", "email", "profile"]`                                        | JSON list of OIDC scopes to request. The OIDC IDP will need to send the group attribute. |
 | `IDINVITE_OIDC_USER_ATTR`           | `email`                                                                 | The attribute to use as the user ID.                                                     |
 | `HMDOORIS_REQUIRES_GROUP`           | -                                                                       | Set to require users to be a member of this groups.                                      |
+| `HMDOORIS_SPACEAPI_OPEND_NAME`      | -                                                                       | Name of the device to send `spaceapid` updates for                                       |
+| `HMDOORIS_SPACEAPI_OPEN_URL`        | -                                                                       | URL for the `spaceapid` open update endpoint.                                            |
 | `HMDOORIS_URL`                      | `http://localhost:3000`                                                 | URL of the application, used to construct links to itself.                               |
 
 ### Required Group
@@ -34,6 +36,14 @@ RaspberryMatic. If you are using a private certificate, you will need to use `HM
 the HTTP client to a suitable CA certificate. Setting the variable to `false` will disable certificate verification.
 Alternatively, you can use plain `http`.
 
+### SpaceAPI
+
+[spaceapid](https://git.hamburg.ccc.de/CCCHH/spaceapid) can be used to provide data
+for [SpaceAPI](https://spaceapi.io), and it's open update endpoint can be used to report the open status of a space. By
+setting `HMDOORIS_SPACEAPI_OPEND_NAME` to the name of the lock on the main door, and `HMDOORIS_SPACEAPI_OPEN_URL` to the
+update endpoint URL hmdooris can update the open status whenever it changes. Add the username and password in the url,
+in the `https://user:pass@hostname.tld` format. If you do not set the name, no updates will be sent.
+
 ## Managing the CCU certificate
 
 If you want to talk to the RaspberryMatic/CCU-Jack and you are using a self-signed certificate (which is the default),