fix: Capitalize "Custom attributes" in documentation

- Updated the list of topics in several documentation files to capitalize "Custom attributes" for consistency and proper formatting.

en/manual/animation/additive-animation.md

@@ -137,4 +137,4 @@ You can use additive animations with animations that use the same skeleton and s
 * [Animation scripts](animation-scripts.md)
 * [Procedural animation](procedural-animation.md)
 * [Custom blend trees](custom-blend-trees.md)
-* [custom attributes](custom-attributes.md)
+* [Custom attributes](custom-attributes.md)

en/manual/animation/animation-scripts.md

@@ -110,4 +110,4 @@ You can also override the animation blend tree and do all animation blending in
 * [Procedural animation](procedural-animation.md)
 * [Custom blend trees](custom-blend-trees.md)
 * [Model node links](model-node-links.md)
-* [custom attributes](custom-attributes.md)
+* [Custom attributes](custom-attributes.md)

en/manual/animation/custom-blend-trees.md

@@ -108,4 +108,4 @@ public class AnimationBlendTree : SyncScript, IBlendTreeBuilder
 * [Additive animation](additive-animation.md)
 * [Procedural animation](procedural-animation.md)
 * [Model node links](model-node-links.md)
-* [custom attributes](custom-attributes.md)
+* [Custom attributes](custom-attributes.md)

en/manual/animation/import-animations.md

@@ -63,4 +63,4 @@ To use an animation asset, add an [AnimationComponent](xref:Stride.Engine.Animat
 * [Procedural animation](procedural-animation.md)
 * [Custom blend trees](custom-blend-trees.md)
 * [Model node links](model-node-links.md)
-* [custom attributes](custom-attributes.md)
+* [Custom attributes](custom-attributes.md)

en/manual/animation/index.md

@@ -53,4 +53,4 @@ The templates **First-person shooter**, **Third-person platformer** and **Top-do
 * [Procedural animation](procedural-animation.md)
 * [Custom blend trees](custom-blend-trees.md)
 * [Model node links](model-node-links.md)
-* [custom attributes](custom-attributes.md)
+* [Custom attributes](custom-attributes.md)

en/manual/animation/preview-animations.md

@@ -48,4 +48,4 @@ The animation preview uses the model selected in the **preview model** in the **
 * [Procedural animation](procedural-animation.md)
 * [Custom blend trees](custom-blend-trees.md)
 * [Model node links](model-node-links.md)
-* [custom attributes](custom-attributes.md)
+* [Custom attributes](custom-attributes.md)

en/manual/animation/procedural-animation.md

@@ -139,4 +139,4 @@ public class AnimationLight : StartupScript
 * [Additive animation](additive-animation.md)
 * [Custom blend trees](custom-blend-trees.md)
 * [Model node links](model-node-links.md)
-* [custom attributes](custom-attributes.md)
+* [Custom attributes](custom-attributes.md)