DOC: Add feature support by pypdf (#2738)

Author: j-t-1

docs/user/pdf-version-support.md

@@ -18,14 +18,14 @@ all features of PDF 2.0.
 
 ## PDF Feature Support by pypdf
 
-| Feature                                 | PDF-Version | pypdf Support |
-| --------------------------------------- | ----------- | -------------- |
-| Transparent Graphics                    | 1.4         | ?              |
+| Feature                                 | PDF Version | pypdf Support  |
+| --------------------------------------- |:-----------:|:--------------:|
 | CMaps                                   | 1.4         | ✅             |
-| Object Streams                          | 1.5         | ?              |
-| Cross-reference Streams                 | 1.5         | ?              |
-| Optional Content Groups (OCGs) - Layers | 1.5         | ?              |
-| Content Stream Compression              | 1.5         | ?              |
+| Transparent Graphics                    | 1.4         | ✅             |
+| Content Stream Compression              | 1.5         | ✅             |
+| Cross-reference Streams                 | 1.5         | ❓             |
+| Object Streams                          | 1.5         | ✅             |
+| Optional Content Groups (OCGs)          | 1.5         | ❓             |
 | AES Encryption                          | 1.6         | ✅             |
 
 See [History of PDF](https://en.wikipedia.org/wiki/History_of_PDF) for more

tests/test_generic.py

@@ -223,7 +223,7 @@ def test_name_object(caplog):
         )
     ) == "/你好世界"
 
-    # to test latin-1 aka stdencoding
+    # to test PDFDocEncoding (latin-1)
     assert (
         NameObject.read_from_stream(BytesIO(b"/DocuSign\xae"), None)
     ) == "/DocuSign®"