add lecture 3 in mmd2

Author: hosamelsafty

teaching/mmdii26/index.md

@@ -34,6 +34,7 @@ This course, offered as part of the *Master's Program in Human Centered Intellig
 ## Lecure Notes
 - Lecture 01: [ZIP Download](https://github.com/AppliedMachineLearning-Lab/mining_media_data_II_SS26/raw/refs/heads/main/MMD_II_SS26_Lecture_01_CourseIntro.zip)
 - Lecture 02: [ZIP Download](https://github.com/AppliedMachineLearning-Lab/mining_media_data_II_SS26/raw/refs/heads/main/MMD_II_SS26_Lecture_02_CED.zip)
+- Lecture 03: [ZIP Download](https://github.com/AppliedMachineLearning-Lab/mining_media_data_II_SS26/raw/refs/heads/main/MMD_II_SS26_Lecture_03.zip)