Clarify difference between Capture and Record audio effects

[RedMser]

Updated documentation of AudioEffectCapture and AudioEffectRecord:

• Capture returns a raw audio buffer, while Record encodes it into an audio stream.
• The note about enable_input setting was confusing in Capture docs, since the microphone use-case is only one of the many listed.
• Additionally, the demo project listed uses the Record effect, not Capture! So moved that note and link to the Record effect instead.
• Record also had a very weird wording in its docs ("It sets, It checks, It returns"...) which I cleaned up.

[fire]

@lyuma I think this looks ok.

[akien-mga]

Thanks!