update weekly notebook (#387)

Author: 1fHu

src/design_notebooks/2025fall/yh4970.md

@@ -1,5 +1,14 @@
 # Simon Hu - Design Notebook (Fall 2025)
 
+## Week 2 (Sep 15- Sep 21)
+- Read Risc 16 datasheet
+- Understood Program counter
+- Wrote code for p.c. of Risc 16
+- Compared the code with group partners
+- Uploaded the code to github repo 
+    (https://github.com/1fHu/ProcessorDesign/blob/main/pc16.v)
+- Finished HDLBits Vector
+
 ## Week 1 (Sep 9–Sep 14)
 - Doing onboarding and finshed repo setup
 - finished HDLBits Getting Started and Verilog language basics