doc: Sync classref with current source

Move EditorSceneImporterFBX doc to its module folder.

modules/fbx/doc_classes/EditorSceneImporterFBX.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="EditorSceneImporterFBX" inherits="EditorSceneImporter" version="3.2">
+	<brief_description>
+		FBX 3D asset importer.
+	</brief_description>
+	<description>
+		This is an FBX 3D asset importer with full support for most FBX features.
+		If exporting a FBX scene from Autodesk Maya, use these FBX export settings:
+		[codeblock]
+		- Smoothing Groups
+		- Smooth Mesh
+		- Triangluate (for meshes with blend shapes)
+		- Bake Animation
+		- Resample All
+		- Deformed Models
+		- Skins
+		- Blend Shapes
+		- Curve Filters
+		- Constant Key Reducer
+		- Auto Tangents Only
+		- *Do not check* Constraints (as it will break the file)
+		- Can check Embed Media (embeds textures into the exported FBX file)
+		  - Note that when importing embedded media, the texture and mesh will be a single immutable file.
+		  - You will have to re-export then re-import the FBX if the texture has changed.
+		- Units: Centimeters
+		- Up Axis: Y
+		- Binary format in FBX 2017
+		[/codeblock]
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+	</methods>
+	<constants>
+	</constants>
+</class>