Add custom-debug-render feature (dimforge#583)

Provide features to enable `rapier/debug-render` when implementing custom debug render

---------

Co-authored-by: Thierry Berger <[email protected]>

Author: jeyum2

Diff for: bevy_rapier2d/Cargo.toml

@@ -37,6 +37,8 @@ debug-render-3d = [
     "rapier2d/debug-render",
     "bevy/bevy_asset",
 ]
+rapier-debug-render = ["rapier2d/debug-render"]
+
 parallel = ["rapier2d/parallel"]
 simd-stable = ["rapier2d/simd-stable"]
 simd-nightly = ["rapier2d/simd-nightly"]

Diff for: bevy_rapier3d/Cargo.toml

@@ -38,6 +38,8 @@ debug-render-3d = [
     "rapier3d/debug-render",
     "bevy/bevy_asset",
 ]
+rapier-debug-render = ["rapier3d/debug-render"]
+
 parallel = ["rapier3d/parallel"]
 simd-stable = ["rapier3d/simd-stable"]
 simd-nightly = ["rapier3d/simd-nightly"]