docs: add release notes

Author: darioAnongba

docs/release-notes/release-notes-0.7.0.md

@@ -168,6 +168,10 @@
   user to specify a custom amount to send to a V2 address that doesn't have an
   amount specified.
 
+- The `BurnAsset` RPC has a new field `asset` that allows the user to specify
+  the asset to burn by ID or GroupKey. The previous `asset` field is deprecated
+  and renamed as `asset_legacy`.
+
 ## tapcli Additions
 
 - [Rename](https://github.com/lightninglabs/taproot-assets/pull/1682) the mint
@@ -182,6 +186,9 @@
   allows users to specify the amount to send to a V2 address that allows custom
   amounts (which is the case when a V2 address is created with an amount of 0).
 
+- The `tapcli assets burn` command now has a new flag `--group_key` that
+  allows users to burn assets by group key.
+
 # Improvements
 
 ## Functional Updates