fix changelog md format

CHANGELOG.md

@@ -494,7 +494,9 @@ All other changes are collected [in this PR](https://github.com/MakieOrg/Makie.j
 - Fixed rendering of `heatmap`s with one or more reversed ranges in CairoMakie, as in `heatmap(1:10, 10:-1:1, rand(10, 10))` [#1100](https://github.com/MakieOrg/Makie.jl/pull/1100).
 - Fixed volume slice recipe and added docs for it [#1123](https://github.com/MakieOrg/Makie.jl/pull/1123).
 
-[Unreleased]: https://github.com/MakieOrg/Makie.jl/compare/v0.20.9...HEAD
+[Unreleased]: https://github.com/MakieOrg/Makie.jl/compare/v0.21.0...HEAD
+[0.21.0]: https://github.com/MakieOrg/Makie.jl/compare/v0.20.9...v0.21.0
+[0.20.10]: https://github.com/MakieOrg/Makie.jl/compare/v0.20.9...v0.20.10
 [0.20.9]: https://github.com/MakieOrg/Makie.jl/compare/v0.20.8...v0.20.9
 [0.20.8]: https://github.com/MakieOrg/Makie.jl/compare/v0.20.7...v0.20.8
 [0.20.7]: https://github.com/MakieOrg/Makie.jl/compare/v0.20.6...v0.20.7
@@ -540,3 +542,4 @@ All other changes are collected [in this PR](https://github.com/MakieOrg/Makie.j
 [0.15.3]: https://github.com/MakieOrg/Makie.jl/compare/v0.15.2...v0.15.3
 [0.15.2]: https://github.com/MakieOrg/Makie.jl/compare/v0.15.1...v0.15.2
 [0.15.1]: https://github.com/MakieOrg/Makie.jl/compare/v0.15.0...v0.15.1
+[0.15.0]: https://github.com/MakieOrg/Makie.jl/compare/v0.14.2...v0.15.0

docs/copy_changelog.jl

@@ -0,0 +1,18 @@
+all_lines = collect(eachline(joinpath("..", "CHANGELOG.md")))
+links = Dict{String,String}()
+kept_lines = filter(all_lines) do line
+    islink = match(r"\[(Unreleased|\d+\.\d+\.\d+)\]: http.*", line) !== nothing
+    if islink
+        placeholder, url = split(line, ": ", limit = 2)
+        links[placeholder] = url
+    end
+    return !islink
+end
+open(joinpath("src", "news.md"), "w") do io
+    for line in kept_lines
+        println(io, replace(line, r"## \[(Unreleased|\d+\.\d+\.\d+)\]" => function (str)
+        url = links[str[4:end]]
+        "$str($url)"
+    end))
+    end
+end