Fix a very slight grammatical issue

doc/classes/PackedFloat32Array.xml

@@ -192,7 +192,7 @@
 		<method name="to_byte_array" qualifiers="const">
 			<return type="PackedByteArray" />
 			<description>
-				Returns a copy of the data converted to a [PackedByteArray], where each element have been encoded as 4 bytes.
+				Returns a copy of the data converted to a [PackedByteArray], where each element has been encoded as 4 bytes.
 				The size of the new array will be [code]float32_array.size() * 4[/code].
 			</description>
 		</method>

doc/classes/PackedFloat64Array.xml

@@ -193,7 +193,7 @@
 		<method name="to_byte_array" qualifiers="const">
 			<return type="PackedByteArray" />
 			<description>
-				Returns a copy of the data converted to a [PackedByteArray], where each element have been encoded as 8 bytes.
+				Returns a copy of the data converted to a [PackedByteArray], where each element has been encoded as 8 bytes.
 				The size of the new array will be [code]float64_array.size() * 8[/code].
 			</description>
 		</method>

doc/classes/PackedInt32Array.xml

@@ -186,7 +186,7 @@
 		<method name="to_byte_array" qualifiers="const">
 			<return type="PackedByteArray" />
 			<description>
-				Returns a copy of the data converted to a [PackedByteArray], where each element have been encoded as 4 bytes.
+				Returns a copy of the data converted to a [PackedByteArray], where each element has been encoded as 4 bytes.
 				The size of the new array will be [code]int32_array.size() * 4[/code].
 			</description>
 		</method>

doc/classes/PackedInt64Array.xml

@@ -187,7 +187,7 @@
 		<method name="to_byte_array" qualifiers="const">
 			<return type="PackedByteArray" />
 			<description>
-				Returns a copy of the data converted to a [PackedByteArray], where each element have been encoded as 8 bytes.
+				Returns a copy of the data converted to a [PackedByteArray], where each element has been encoded as 8 bytes.
 				The size of the new array will be [code]int64_array.size() * 8[/code].
 			</description>
 		</method>

doc/classes/SurfaceTool.xml

@@ -147,7 +147,7 @@
 		<method name="generate_tangents">
 			<return type="void" />
 			<description>
-				Generates a tangent vector for each vertex. Requires that each vertex have UVs and normals set already (see [method generate_normals]).
+				Generates a tangent vector for each vertex. Requires that each vertex already has UVs and normals set (see [method generate_normals]).
 			</description>
 		</method>
 		<method name="get_aabb" qualifiers="const">