Changelog: add window.matchMedia & MediaQueryList

Separated so it’s easier to overlay patches without conflicts in
changelog.

Author: toastal

CHANGES.md

@@ -39,6 +39,7 @@
 * Compiler: deadcode elimination of cyclic values (#1978)
 * Compiler: directly write Wasm binary modules (#2000, #2003)
 * Compiler: rewrote inlining pass (#1935, #2018)
+* Library: add Dom_html.window.matchMedia & Dom_html.mediaQueryList (#2017)
 
 ## Bug fixes
 * Compiler: fix stack overflow issues with double translation (#1869)