Update graphics effect docs

Author: adazem009

docs/Graphics effects.md

@@ -1,21 +1,10 @@
 \page graphicsEffects Graphics effects
 
-libscratchcpp provides API for implementing custom graphics effects.
-No effects are currently included with libscratchcpp, but that is planned to change.
+libscratchcpp provides API for adding custom graphics effects.
+No effects are included with libscratchcpp and must be implemented by the project player.
 
-In case you've implemented some of the effects yourself, feel free to make pull requests!
-These are the issues (tasks) for the default graphics effects:
-
-- Color: https://github.com/scratchcpp/libscratchcpp/issues/283
-- Fisheye: https://github.com/scratchcpp/libscratchcpp/issues/284
-- Whirl: https://github.com/scratchcpp/libscratchcpp/issues/285
-- Pixelate: https://github.com/scratchcpp/libscratchcpp/issues/286
-- Mosaic: https://github.com/scratchcpp/libscratchcpp/issues/287
-- Brightness: https://github.com/scratchcpp/libscratchcpp/issues/288
-- Ghost: https://github.com/scratchcpp/libscratchcpp/issues/289
-
-# Implementing a graphics effect
-To implement a graphics effect that libscratchcpp doesn't support,
+# Adding a custom graphics effect
+To add a graphics effect that libscratchcpp doesn't support,
 subclass \link libscratchcpp::IGraphicsEffect IGraphicsEffect \endlink
 and override all of the methods.
 
@@ -27,12 +16,14 @@ using namespace libscratchcpp;
 The `name()` method should return the name of the effect which is
 used by the set and change effect blocks, for example `ghost` or `fisheye`.
 
-The `apply()` method is used to apply the effect on a bitmap. The bitmap
-can be accessed using the `bitmap` parameter and is writable.
-
 # Registering the graphics effect
 To register the graphics effect, use \link libscratchcpp::ScratchConfiguration::registerGraphicsEffect() ScratchConfiguration::registerGraphicsEffect() \endlink.
 
 ```cpp
 libscratchcpp::ScratchConfiguration::registerGraphicsEffect(std::make_shared<MyGraphicsEffect>());
 ```
+
+# Why should effects be registered?
+Effects in Scratch are usually identified by their name (`ghost`, `brightness`, etc.), but this isn't effective
+when it comes to running projects. Those "names" are therefore replaced by \link libscratchcpp::IGraphicsEffect IGraphicsEffect \endlink
+pointers which makes working with effects faster.