update READMEs of JS packages (#96)

## Summary

Make the README disclaimer about the 0.x version less offputting.

## How did you test this change?

CI

## Are there any deployment considerations?

changeset

## Does this work require review from our design team?

no

Author: Vadman97

.changeset/little-suits-leave.md

@@ -0,0 +1,7 @@
+---
+'@launchdarkly/observability-node': patch
+'@launchdarkly/session-replay': patch
+'@launchdarkly/observability': patch
+---
+
+update README EAP notice

sdk/@launchdarkly/observability-node/README.md

@@ -5,10 +5,7 @@
 [![NPM][o11y-sdk-dm-badge]][o11y-sdk-npm-link]
 [![NPM][o11y-sdk-dt-badge]][o11y-sdk-npm-link]
 
-# Early Access Preview️
-
-> [!CAUTION]
-> This library is a alpha version and should not be considered ready for production use while this message is visible.
+**NB: APIs are subject to change until a 1.x version is released.**
 
 ## Install
 

sdk/@launchdarkly/observability/README.md

@@ -5,10 +5,7 @@
 [![NPM][o11y-sdk-dm-badge]][o11y-sdk-npm-link]
 [![NPM][o11y-sdk-dt-badge]][o11y-sdk-npm-link]
 
-# Early Access Preview️
-
-> [!CAUTION]
-> This library is in Early Access Preview and APIs are subject to change until a 1.x version is released.
+**NB: APIs are subject to change until a 1.x version is released.**
 
 ## Install
 

sdk/@launchdarkly/session-replay/README.md

@@ -5,10 +5,7 @@
 [![NPM][o11y-sdk-dm-badge]][o11y-sdk-npm-link]
 [![NPM][o11y-sdk-dt-badge]][o11y-sdk-npm-link]
 
-# Early Access Preview️
-
-> [!CAUTION]
-> This library is in Early Access Preview and APIs are subject to change until a 1.x version is released.
+**NB: APIs are subject to change until a 1.x version is released.**
 
 ## Install