DocData: Re-expose parametric setters and getters

Setters and getters have been hidden from the documentation when the matching
properties have been exposed, but some of them are parametric and require the
name or index of a given parameter to be used. So they need to be properly
documented with the type and name of the arguments they take.

For example, CPUParticles' `set_param(Parameter param, float value)`.

doc/classes/StreamTexture.xml

@@ -9,6 +9,14 @@
 	<tutorials>
 	</tutorials>
 	<methods>
+		<method name="load">
+			<return type="int" enum="Error">
+			</return>
+			<argument index="0" name="path" type="String">
+			</argument>
+			<description>
+			</description>
+		</method>
 	</methods>
 	<members>
 		<member name="load_path" type="String" setter="load" getter="get_load_path" default="&quot;&quot;">