Added toc to readme

god github's video thing is scuffed...

README.md

@@ -1,5 +1,14 @@
 # From Flying Balls to Colliding Polygons
 
+## Table of contents
+
+- [Abstract](#abstract)
+- [Before vs After](#before-vs-after)
+  - [Context](#context)
+  - [Before](#before)
+  - [After](#after)
+- [Contact](#contact)
+
 ## Abstract
 
 > (text taken from the abstract of my report that you can find
@@ -30,6 +39,8 @@ crucial that the simulation code be efficient to obtain smooth animations.
 
 ## Before vs After
 
+### Context
+
 A little of context for the follow videos:
 
 - in the first video, the special ball with an arrow inside is a "spaceship",
@@ -44,11 +55,11 @@ A little of context for the follow videos:
 
 ### Before
 
-![before video](before.webm)
+https://github.com/karma-riuk/flying-balls/assets/30158492/ddc0d608-9667-4a21-8132-e056e443e0e2
 
 ### After
 
-[after video](after.mp4)
+https://github.com/karma-riuk/flying-balls/assets/30158492/bd4013b8-bc01-4d52-aa2f-44dbc25de717
 
 <!-- ## Controls -->
 <!---->