Fixes invalid links to tutorials in AudioStreamGenerator, AudioStreamGeneratorPlayback, and AudioEffectSpectrumAnalyzer class references

(cherry picked from commit b6c543179c26636a1d78d55b78cb23f42e24917e)

doc/classes/AudioEffectSpectrumAnalyzer.xml

@@ -8,8 +8,8 @@
 		See also [AudioStreamGenerator] for procedurally generating sounds.
 	</description>
 	<tutorials>
-		<link title="https://godotengine.org/asset-library/asset/528">Audio Spectrum Demo</link>
-		<link title="https://godotengine.org/article/godot-32-will-get-new-audio-features">Godot 3.2 will get new audio features</link>
+		<link title="Audio Spectrum Demo">https://godotengine.org/asset-library/asset/528</link>
+		<link title="Godot 3.2 will get new audio features">https://godotengine.org/article/godot-32-will-get-new-audio-features</link>
 	</tutorials>
 	<methods>
 	</methods>

doc/classes/AudioStreamGenerator.xml

@@ -10,7 +10,7 @@
 	</description>
 	<tutorials>
 		<link title="Audio Generator Demo">https://godotengine.org/asset-library/asset/526</link>
-		<link title="https://godotengine.org/article/godot-32-will-get-new-audio-features">Godot 3.2 will get new audio features</link>
+		<link title="Godot 3.2 will get new audio features">https://godotengine.org/article/godot-32-will-get-new-audio-features</link>
 	</tutorials>
 	<methods>
 	</methods>

doc/classes/AudioStreamGeneratorPlayback.xml

@@ -8,7 +8,7 @@
 	</description>
 	<tutorials>
 		<link title="Audio Generator Demo">https://godotengine.org/asset-library/asset/526</link>
-		<link title="https://godotengine.org/article/godot-32-will-get-new-audio-features">Godot 3.2 will get new audio features</link>
+		<link title="Godot 3.2 will get new audio features">https://godotengine.org/article/godot-32-will-get-new-audio-features</link>
 	</tutorials>
 	<methods>
 		<method name="can_push_buffer" qualifiers="const">