feat: add image license info

content/page/text-api-specs.md

@@ -174,6 +174,7 @@ The URI can have one of the following forms:
 |----|----|----|----|
 | id | 1 | URI | URI pointing to the image |
 | manifest | ? | URL | URL pointing to the image's manifest object |
+| license | 1 | [License Object](#license-object) | the license for the image that MUST be used |
 
 ### License Object
 
@@ -183,6 +184,7 @@ It is REQUIRED to use one of [SPDX](https://spdx.org/licenses/).
 | Field Name | Cardinality | Type | Description |
 |----|----|----|----|
 | id | 1 | SPDX | an SPDX identifier |
+| notes | ? | string | further notes concerning the license. can be used e.g. for the attribution statement of CC BY |
 
 ### Sequence Object
 
@@ -213,7 +215,7 @@ Within a manifest it SHOULD contain items exclusively.
 
 ### Class Diagram
 
-![UML class diagram](http://yuml.me/842a943b.png)
+![UML class diagram](https://yuml.me/64bc7976.png)
 
 ```yuml
 // Ahiqar TextAPI
@@ -233,7 +235,7 @@ Within a manifest it SHOULD contain items exclusively.
 
 [Image| -id; -manifest]
 
-[License| -id 1]
+[License| -id 1; -notes ?]
 
 [Title| -title 1; -type 1]
 
@@ -253,6 +255,8 @@ Within a manifest it SHOULD contain items exclusively.
 [Item]-[Image]
 
 [Actor]-[Idref]
+
+[Image]-[License]
 ```
 
 ### Example Objects
@@ -365,7 +369,12 @@ Within a manifest it SHOULD contain items exclusively.
   ],
   "x-langString": "Arabic, Classical Syriac, Eastern Syriac, English, Karshuni, Latin, Western Syriac",
   "image": {
-    "id": "https://ahikar.sub.uni-goettingen.de/api/images/3r1gj"
+    "id": "https://ahikar.sub.uni-goettingen.de/api/images/3r1gj",
+    "license":
+      {
+        "id": "CC-BY-SA-4.0",
+        "notes": "Provided by some other data source."
+      }
   },
   "annotationCollection": "https://ahikar.sub.uni-goettingen.de/api/textapi/ahikar/3r9ps/3r1gh/140/annotationCollection.json"
 }