Update Importing 3D scenes link to match splitting PR

See godotengine/godot-docs#7830

doc/classes/EditorScenePostImport.xml

@@ -55,7 +55,7 @@
  [/codeblocks]
  </description>
  <tutorials>
- <link title="Importing 3D scenes: Custom script">$DOCS_URL/tutorials/assets_pipeline/importing_scenes.html#custom-script</link>
+ <link title="Importing 3D scenes: Configuration: Using import scripts for automation">$DOCS_URL/tutorials/assets_pipeline/importing_3d_scenes/import_configuration.html#using-import-scripts-for-automation</link>
  </tutorials>
  <methods>
  <method name="_post_import" qualifiers="virtual">

doc/classes/ResourceImporterOBJ.xml

@@ -8,7 +8,7 @@
  See also [ResourceImporterScene], which is used for more advanced 3D formats such as glTF.
  </description>
  <tutorials>
- <link title="Importing 3D scenes">$DOCS_URL/tutorials/assets_pipeline/importing_scenes.html</link>
+ <link title="Importing 3D scenes">$DOCS_URL/tutorials/assets_pipeline/importing_3d_scenes/index.html</link>
  </tutorials>
  <members>
  <member name="generate_tangents" type="bool" setter="" getter="" default="true">

doc/classes/ResourceImporterScene.xml

@@ -9,7 +9,7 @@
  [b]Note:[/b] [ResourceImporterScene] is [i]not[/i] used for [PackedScene]s, such as [code].tscn[/code] and [code].scn[/code] files.
  </description>
  <tutorials>
- <link title="Importing 3D scenes">$DOCS_URL/tutorials/assets_pipeline/importing_scenes.html</link>
+ <link title="Importing 3D scenes">$DOCS_URL/tutorials/assets_pipeline/importing_3d_scenes/index.html</link>
  </tutorials>
  <members>
  <member name="_subresources" type="Dictionary" setter="" getter="" default="{}">
@@ -28,7 +28,7 @@
  If [code]true[/code], trim the beginning and end of animations if there are no keyframe changes. This can reduce output file size and memory usage with certain 3D scenes, depending on the contents of their animation tracks.
  </member>
  <member name="import_script/path" type="String" setter="" getter="" default="&quot;&quot;">
- Path to an import script, which can run code after the import process has completed for custom processing. See [url=$DOCS_URL/tutorials/assets_pipeline/importing_scenes.html#doc-importing-3d-scenes-import-script]Using import scripts for automation[/url] for more information.
+ Path to an import script, which can run code after the import process has completed for custom processing. See [url=$DOCS_URL/tutorials/assets_pipeline/importing_3d_scenes/import_configuration.html#using-import-scripts-for-automation]Using import scripts for automation[/url] for more information.
  </member>
  <member name="meshes/create_shadow_meshes" type="bool" setter="" getter="" default="true">
  If [code]true[/code], enables the generation of shadow meshes on import. This optimizes shadow rendering without reducing quality by welding vertices together when possible. This in turn reduces the memory bandwidth required to render shadows. Shadow mesh generation currently doesn't support using a lower detail level than the source mesh (but shadow rendering will make use of LODs when relevant).