added upcoming release info

Author: thomasWeise

README.md

@@ -89,6 +89,7 @@ Hier finden Sie die Slides zum Kurs in deutscher Sprache:
 
 The following complete packages are available:
 
+- [`2026.06.17`](https://github.com/thomasWeise/programmingWithPython/releases/download/2026.03.04/programmingWithPython_2026_06_17.tar.xz) provides the end state of the book, slides (in German language), questions, and example sources *after* the lecture period in Summer Semester 2026 (2025-2026学年 第二学期) at Hefei University (合肥大学).
 - [`2026.03.04`](https://github.com/thomasWeise/programmingWithPython/releases/download/2026.03.04/programmingWithPython_2026_03_04.tar.xz) provides the beginning state of the book, slides (in German language), questions, and example sources *before* the lecture period in Summer Semester 2026 (2025-2026学年 第二学期) at Hefei University (合肥大学).
 - [`2025.11.17`](https://github.com/thomasWeise/programmingWithPython/releases/download/2025.11.17/programmingWithPython_2025_11_17.tar.xz) provides the end state of the book, slides (in German language), questions, and example sources *after* the lecture period in Winter Semester 2025/2026 (2025-2026学年 第一学期) at Hefei University (合肥大学).