Refactor section headings in networks index file for consistency

Author: Daniel Precioso

modules/networks/index.qmd

@@ -23,7 +23,7 @@ We will work with real datasets such as the USA flight network and the Enron ema
 
 ## What do we implement?
 
-### 1. Network representation with `networkx`
+### Network representation with `networkx`
 
 You will:
 
@@ -37,7 +37,7 @@ These concepts follow the formal definitions of nodes, links, directed and weigh
 
 ---
 
-### 2. Centrality and node importance
+### Centrality and node importance
 
 We implement:
 
@@ -54,7 +54,7 @@ You will see how importance affects spreading processes.
 
 ---
 
-### 3. Network models
+### Network models
 
 We generate synthetic networks to compare structure:
 
@@ -73,7 +73,7 @@ You will measure:
 
 ---
 
-### 4. Spreading processes on networks: SIS and SIR
+### Spreading processes on networks: SIS and SIR
 
 This is the core computational part of the lab.