Add SIP-019 to README.md

Author: MarvinJanssen

README.md

@@ -8,7 +8,7 @@ may submit a SIP.
 
 ## SIPs in the Process of Being Activated
 
-* [SIP-019](https://github.com/stacksgov/sips/pull/72): Notifications for Token Metadata Updates
+* None
 
 ## Ratified SIPs
 
@@ -35,6 +35,7 @@ may submit a SIP.
 * [SIP-015](./sips/sip-015/sip-015-network-upgrade.md): Stacks Upgrade of Proof-of-Transfer and Clarity
 * [SIP-016](./sips/sip-016/sip-016-token-metadata.md): Metadata for Tokens
 * [SIP-018](./sips/sip-018/sip-018-signed-structured-data.md): Signed Structured Data
+* [SIP-019](./sips/sip-019/sip-019-token-metadata-update-notifications.md): Notifications for Token Metadata Updates
 * [SIP-020](./sips/sip-020/sip-020-bitwise-ops.md): Bitwise Operations in Clarity
 
 ## How to Get Involved