doc: Remove extraneous empty lines in descriptions

doc/classes/AudioEffectEQ10.xml

@@ -16,7 +16,6 @@
 		Band 8 : 4000 Hz
 		Band 9 : 8000 Hz
 		Band 10 : 16000 Hz
-
 		See also [AudioEffectEQ], [AudioEffectEQ6], [AudioEffectEQ21].
 	</description>
 	<tutorials>

doc/classes/AudioEffectEQ21.xml

@@ -27,7 +27,6 @@
 		Band 19 : 11000 Hz
 		Band 20 : 16000 Hz
 		Band 21 : 22000 Hz
-
 		See also [AudioEffectEQ], [AudioEffectEQ6], [AudioEffectEQ10].
 	</description>
 	<tutorials>

doc/classes/AudioEffectEQ6.xml

@@ -12,7 +12,6 @@
 		Band 4 : 1000 Hz
 		Band 5 : 3200 Hz
 		Band 6 : 10000 Hz
-
 		See also [AudioEffectEQ], [AudioEffectEQ10], [AudioEffectEQ21].
 	</description>
 	<tutorials>

doc/classes/EditorImportPlugin.xml

@@ -5,10 +5,7 @@
 	</brief_description>
 	<description>
 		EditorImportPlugins provide a way to extend the editor's resource import functionality. Use them to import resources from custom files or to provide alternatives to the editor's existing importers. Register your [EditorPlugin] with [method EditorPlugin.add_import_plugin].
-
 		EditorImportPlugins work by associating with specific file extensions and a resource type. See [method get_recognized_extension] and [method get_resource_type]). They may optionally specify some import presets that affect the import process. EditorImportPlugins are responsible for creating the resources and saving them in the [code].import[/code] directory.
-
-
 		Below is an example EditorImportPlugin that imports a [Mesh] from a file with the extension ".special" or ".spec":
 		[codeblock]
 		tool

doc/classes/Engine.xml

@@ -16,7 +16,6 @@
 			</return>
 			<description>
 				Returns engine author information in a Dictionary.
-
 				"lead_developers" - Array of Strings, lead developer names
 				"founders" - Array of Strings, founder names
 				"project_managers" - Array of Strings, project manager names
@@ -28,7 +27,6 @@
 			</return>
 			<description>
 				Returns an Array of copyright information Dictionaries.
-
 				"name" - String, component name
 				"parts" - Array of Dictionaries {"files", "copyright", "license"} describing subsections of the component
 			</description>
@@ -89,7 +87,6 @@
 			</return>
 			<description>
 				Returns the current engine version information in a Dictionary.
-
 				"major"    - Holds the major version number as an int
 				"minor"    - Holds the minor version number as an int
 				"patch"    - Holds the patch version number as an int

doc/classes/OS.xml

@@ -292,7 +292,6 @@
 			</argument>
 			<description>
 				Returns the dots per inch density of the specified screen.
-
 				On Android Devices, the actual screen densities are grouped into six generalized densities:
 					ldpi    - 120 dpi
 					mdpi    - 160 dpi

doc/classes/Quat.xml

@@ -6,7 +6,6 @@
 	<description>
 		A unit quaternion used for representing 3D rotations.
 		It is similar to [Basis], which implements matrix representation of rotations, and can be parametrized using both an axis-angle pair or Euler angles. But due to its compactness and the way it is stored in memory, certain operations (obtaining axis-angle and performing SLERP, in particular) are more efficient and robust against floating point errors.
-
 		Quaternions need to be (re)normalized.
 	</description>
 	<tutorials>

doc/classes/Skeleton.xml

@@ -5,11 +5,8 @@
 	</brief_description>
 	<description>
 		Skeleton provides a hierarchical interface for managing bones, including pose, rest and animation (see [Animation]). Skeleton will support rag doll dynamics in the future.
-
 		The overall transform of a bone with respect to the skeleton is determined by the following hierarchical order: rest pose, custom pose and pose.
-
 		Note that "global pose" below refers to the overall transform of the bone with respect to skeleton, so it not the actual global/world transform of the bone.
-
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/Spatial.xml

@@ -5,7 +5,6 @@
 	</brief_description>
 	<description>
 		Most basic 3D game object, with a 3D [Transform] and visibility settings. All other 3D game objects inherit from Spatial. Use Spatial as a parent node to move, scale, rotate and show/hide children in a 3D project.
-
 		Affine operations (rotate, scale, translate) happen in parent's local coordinate system, unless the Spatial object is set as top level. Affine operations in this coordinate system correspond to direct affine operations on the Spatial's transform. The word local below refers to this coordinate system. The coordinate system that is attached to the Spatial object itself is referred to as object-local coordinate system.
 	</description>
 	<tutorials>
@@ -284,7 +283,6 @@
 		</member>
 		<member name="rotation" type="Vector3" setter="set_rotation" getter="get_rotation">
 			Rotation part of the local transformation, specified in terms of YXZ-Euler angles in the format (X-angle, Y-angle, Z-angle), in radians.
-
 			Note that in the mathematical sense, rotation is a matrix and not a vector. The three Euler angles, which are the three indepdent parameters of the Euler-angle parametrization of the rotation matrix, are stored in a [Vector3] data structure not because the rotation is a vector, but only because [Vector3] exists as a convenient data-structure to store 3 floating point numbers. Therefore, applying affine operations on the rotation "vector" is not meaningful.
 		</member>
 		<member name="rotation_degrees" type="Vector3" setter="set_rotation_degrees" getter="get_rotation_degrees">

doc/classes/ToolButton.xml

@@ -5,7 +5,6 @@
 	</brief_description>
 	<description>
 		This is a helper class to generate a flat [Button] (see [method Button.set_flat]), creating a ToolButton is equivalent to:
-
 		[codeblock]
 		var btn = Button.new()
 		btn.set_flat(true)