chore(docs): line length too long

Author: jeertmans

docs/source/reference/api.md

@@ -1,8 +1,10 @@
 # Application Programming Interface
 
-Manim Slides' API is very limited: it simply consists of two classes, `Slide` and `ThreeDSlide`, which are subclasses of `Scene` and `ThreeDScene` from Manim.
+Manim Slides' API is very limited: it simply consists of two classes, `Slide`
+and `ThreeDSlide`, which are subclasses of `Scene` and `ThreeDScene` from Manim.
 
-Therefore, we only document here the methods we think the end-user will ever use, not the methods used internally when rendering.
+Therefore, we only document here the methods we think the end-user will ever
+use, not the methods used internally when rendering.
 
 ```{eval-rst}
 .. autoclass:: manim_slides.Slide