bip390: Update to Specification type

README.mediawiki

@@ -1413,7 +1413,7 @@ users (see also: [https://en.bitcoin.it/wiki/Economic_majority economic majority
 | Applications
 | musig() Descriptor Key Expression
 | Ava Chow
-| Informational
+| Specification
 | Draft
 |- style="background-color: #ffcfcf"
 | [[bip-0391.mediawiki|391]]

bip-0390.mediawiki

@@ -4,7 +4,7 @@
   Title: musig() Descriptor Key Expression
   Authors: Ava Chow <me@achow101.com>
   Status: Draft
-  Type: Informational
+  Type: Specification
   Assigned: 2024-06-04
   License: CC0-1.0
   Version: 0.2.0