Merge BlockstreamResearch/SimplicityHL#215: update CHANGELOG.md #14

Job	Run time
Check WASM	35s
Docs - stable toolchain (recent)	55s
Test - stable toolchain	3m 52s
Prepare	3s
Check Fuzz	43s
Test - MSRV	4m 14s
Lint - nightly toolchain (recent)	48s
Docs - nightly toolchain (recent)	1m 8s
Format - nightly toolchain	15s
Test - nightly toolchain	3m 55s
	16m 28s

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