docs: add a note about participant list truncation and livestreaming use case (#1559)

Author: myandrienko

packages/client/docusaurus/docs/javascript/02-guides/03-call-and-participant-state.mdx

@@ -151,6 +151,8 @@ const subscription = call.state.participants$.subscribe((participants) => {
 subscription.unsubscribe();
 ```
 
+In a call with many participants, the value of the `participants$` call state observable is truncated to 250 participants. The participants who are publishing video, audio, or screen sharing have priority over the other participants in the list. This means, for example, that in a livestream with one host and many viewers, the host is guaranteed to be in the list.
+
 ## Client state
 
 The client state can be accessed by `client.state`.

packages/react-native-sdk/docusaurus/docs/reactnative/03-core/03-call-and-participant-state.mdx

@@ -205,10 +205,12 @@ const hosts = participants.filter((p) => p.roles.includes('host'));
 
 // participants that publish video and audio
 const videoParticipants = participants.filter(
-  (p) => hasVideo(p) && hasAudio(p),
+  (p) => hasVideo(p) && hasAudio(p)
 );
 ```
 
+In a call with many participants, the list returned by the `useParticipants` call state hook is truncated to 250 participants. The participants who are publishing video, audio, or screen sharing have priority over the other participants in the list. This means, for example, that in a livestream with one host and many viewers, the host is guaranteed to be in the list.
+
 ## Client state
 
 To observe client state you need to provide a `StreamVideoClient` instance to the `StreamVideo` context provider.

packages/react-sdk/docusaurus/docs/React/02-guides/03-call-and-participant-state.mdx

@@ -207,6 +207,8 @@ const videoParticipants = participants.filter(
 );
 ```
 
+In a call with many participants, the list returned by the `useParticipants` call state hook is truncated to 250 participants. The participants who are publishing video, audio, or screen sharing have priority over the other participants in the list. This means, for example, that in a livestream with one host and many viewers, the host is guaranteed to be in the list.
+
 ## Client state
 
 To observe client state you need to provide a `StreamVideoClient` instance to the `StreamVideo` context provider.