Mark ADR 18 as adopted (#7358)

Co-authored-by: primer[bot] <119360173+primer[bot]@users.noreply.github.com>
Co-authored-by: Hector Garcia <hectahertz@github.com>

Author: 3 people

contributor-docs/adrs/adr-018-responsive-values.md

@@ -5,7 +5,7 @@
 | Stage    | Status |
 | -------- | ------ |
 | Approved | ✅     |
-| Adopted  | 🚧     |
+| Adopted  | ✅     |
 
 ## Context