Replace inline release notes with link to official release notes page

Summary: Remove inline changelog content from CHANGELOG.md and README.md files across samples, templates, and github repos. Replace with a link to the official release notes page at https://developers.meta.com/horizon/release-notes/?search_key=spatial-sdk so release notes are maintained in a single canonical location.

Reviewed By: pmcgvr

Differential Revision: D101385541

fbshipit-source-id: 739d0c9e5d4eb37f782e2672502a422c28a8c48f

Author: AidanTran

CHANGELOG.md

@@ -1,5 +1,3 @@
 # Changelog
 
-Check out our official [release notes](https://developers.meta.com/horizon/documentation/spatial-sdk/release-notes).
-
-This format is roughly based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
+Check out our official [release notes](https://developers.meta.com/horizon/release-notes/?search_key=spatial-sdk).

README.md

@@ -41,7 +41,7 @@ The documentation for Meta Spatial SDK can be found [here](https://developers.me
 
 ## Release Notes
 
-Find our official release notes [here](https://developers.meta.com/horizon/documentation/spatial-sdk/release-notes).
+Find our official release notes [here](https://developers.meta.com/horizon/release-notes/?search_key=spatial-sdk).
 
 ## Spatial SDK Gradle Plugin