update links for ch4

content/1-simulations/index.md

@@ -40,13 +40,13 @@ Here's a full list of all the simulations and the textbook exercise questions as
 
 ## Chapter 4: Learning
 
-* `self_org`: Self organizing learning using BCM-like dynamic of XCAL (Questions **4.1 -- 4.2**).
+* [self_org](https://compcogneuro.org/sims/ch4/self_org): Self organizing learning using BCM-like dynamic of XCAL (Questions **4.1 -- 4.2**).
 
 * [pat_assoc](https://compcogneuro.org/sims/ch4/pat_assoc): Basic two-layer network learning simple input/output mapping tasks (pattern associator) with Hebbian and Error-driven mechanisms (Questions **4.3 -- 4.6**).
 
 * [err_driven_hidden](https://compcogneuro.org/sims/ch4/err_driven_hidden): Full error-driven learning with a hidden layer, can solve any input output mapping (Question **4.7**).
 
-* `family_trees`: Learning in a deep (multi-hidden-layer) network, showing advantages of combination of self-organizing and error-driven learning (Questions **4.8 -- 4.9**).
+* [family_trees](https://compcogneuro.org/sims/ch4/family_trees): Learning in a deep (multi-hidden-layer) network, showing advantages of combination of self-organizing and error-driven learning (Questions **4.8 -- 4.9**).
 
 * `hebberr_combo`: Hebbian learning in combination with error-driven facilitates generalization (Questions **4.10 -- 4.12**).