Update 3.0.0.md

Author: andreasrosdal

changelogs/3.0.0.md

@@ -3,11 +3,21 @@
 * OpenPDF 3.0.0 uses the new package name **org.openpdf**. The old com.lowagie is now removed from OpenPDF 3.0.
 This means that source code using OpenPDF must be migrated to use import statements using org.openpdf.* package.
 
-* Full PDF 2.0 support in OpenPDF. This is a breaking API change where all version related methods now use
-String instead of char as method parameters. Default version is now PDF 2.0.
+* **PDF 2.0 support in OpenPDF** – This is a **breaking API change**:  
+  All version-related methods now use `String` instead of `char` as method parameters.  
+  The default version is now **PDF 2.0**.
+
+  **About PDF 2.0:**  
+  PDF 2.0 is the latest official version of the Portable Document Format, standardized as **ISO 32000-2:2020**.  
+  It was first published by the International Organization for Standardization (ISO) in **July 2017**, with a revised edition in **December 2020**.  
+  PDF 2.0 introduces improved color management, tagged PDF enhancements, advanced encryption options, and clarifies many ambiguous parts of the PDF 1.x specifications.  
+
+  📄 [Read the PDF 2.0 (ISO 32000-2:2020) specification](https://www.iso.org/standard/75839.html)
+
 
 * Added Html2PdfBatchUtils and PdfBatchUtils, new batch utilities built on Java 21 virtual threads. 
 These APIs improve throughput for HTML→PDF rendering and common PDF tasks such as merge, split, watermark, and encrypt.
 
 
 
+