fixed image links

docs/lectures/dms/01_java_collections.md

@@ -91,7 +91,7 @@ public class Compound {
 }
 ```
 
-![Image](assets/1.png)
+![Image](/lectures/dms/assets/1.png)
 
 *Composition* - The object only exists if the parent object exists, if the parent object is deleted then so is the child object.
 The zoo object owns the compound object. If the zoo object is deleted then the compound object is also deleted.
@@ -102,7 +102,7 @@ public class Zoo {
 }
 ```
 
-![Image](assets/2.png)
+![Image](/lectures/dms/assets/2.png)
 
 **Inheritance**
 A way of forming new classes based on existing classes. Has a "is-a" relationship.
@@ -126,7 +126,7 @@ public class Child extends Parent {
 
 The super keyword called the parent class' constructor.
 
-![Image](assets/3.png)
+![Image](/lectures/dms/assets/3.png)
 
 **What is the difference between an abstract class and an interface**
 - Java abstract class can have instance methods that implement a default behaviour. May contain non-final variables.