Use consistent titles

wiki/src/blueprint/personas.mdwn

@@ -375,7 +375,7 @@ developed by SecondMuse):
   - Publish information about corrupted politicians and harm they did.
   - Turn public opinion against these people.
 
-- **Challenges**
+- **Challenges and threats**
 
   - Access information
   - Publish under pseudonyms
@@ -450,7 +450,7 @@ developed by SecondMuse):
     speak freely and they want other to have access to uncensored
     information.
 
-- **Challenges**
+- **Challenges and threats**
 
   - Use networks
   - Access information online