Add "Collect caller input" guide

fern/llms.txt

@@ -164,7 +164,7 @@ Feature pages are grouped by channel. SDK pages come first when available, follo
 - [Stream call audio](/docs/platform/voice/call-streaming): Stream a live call to your own WebSocket server with SWML, Relay, or REST, then save or process the audio as it arrives, and play audio back into the call on a bidirectional stream.
 - [Conferencing](/docs/server-sdks/reference/python/relay/call/join-conference): Join a call to an ad-hoc audio conference.
 - [Secure payments](/docs/server-sdks/reference/python/relay/call/pay): Collect payment information on a call.
-- [Collect caller input](/docs/server-sdks/reference/python/relay/call/play-and-collect): Play audio and collect speech or key presses.
+- [Collect caller input](/docs/platform/voice/collect-input): Ask the caller a question with SWML, Relay, or Call Flow Builder, collect speech or key presses, branch on the answer, handle silence and unmatched replies, and read the result in the call log or your own code.
 - [Detect machines](/docs/platform/voice/machine-detection): Detect people, voicemail, and fax machines with SWML or Relay. Follow an AMD example and a fax example, handle results, and tune detection.
 - [Noise reduction](/docs/server-sdks/reference/python/relay/call/denoise): Start noise reduction on a call.
 - [Queue calls](/docs/platform/voice/call-queues): Hold callers in a queue and connect each one to the next free agent with SWML or Relay, then track, remove, and manage waiting callers.

fern/products/platform/pages/calling/voice/TTS/speak-text.mdx

@@ -25,6 +25,7 @@ position: 1
 [swml-set]: /docs/swml/reference/calling/set
 [swml-ai-languages]: /docs/swml/reference/calling/ai/languages#use-voice-strings
 [call-commands]: /docs/apis/rest/calls/call-commands
+[collect-input]: /docs/platform/voice/collect-input
 
 Text-to-speech (TTS) reads text aloud on a live call, such as a booking confirmation or a menu.
 You give SignalWire the text and a voice from the [TTS voice catalog][tts-voices], and it speaks
@@ -405,3 +406,4 @@ or `calling.play.volume` with the same `control_id`.
 
 The REST Calling API can't speak and collect input in one step. To speak a menu, start the call
 with a SWML [`prompt`][swml-prompt] or control it from a Relay client.
+[Collect caller input][collect-input] shows both and how to branch on the reply.