doc: adjust RELEASES.md call hierarchy url (#3220)

This links a better description of what the call hierarchy does.

RELEASES.md

@@ -194,7 +194,7 @@ example : x + foo 2 = 12 + x := by
 
 * Modify `InfoTree.context` to facilitate augmenting it with partial contexts while elaborating a command. This breaks backwards compatibility with all downstream projects that traverse the `InfoTree` manually instead of going through the functions in `InfoUtils.lean`, as well as those manually creating and saving `InfoTree`s. See [PR #3159](https://github.com/leanprover/lean4/pull/3159) for how to migrate your code.
 
-* Add language server support for [call hierarchy requests](https://devblogs.microsoft.com/cppblog/c-extension-in-vs-code-1-16-release-call-hierarchy-more/) ([PR #3082](https://github.com/leanprover/lean4/pull/3082)). The change to the .ilean format in this PR means that projects must be fully rebuilt once in order to generate .ilean files with the new format before features like "find references" work correctly again.
+* Add language server support for [call hierarchy requests](https://www.youtube.com/watch?v=r5LA7ivUb2c) ([PR #3082](https://github.com/leanprover/lean4/pull/3082)). The change to the .ilean format in this PR means that projects must be fully rebuilt once in order to generate .ilean files with the new format before features like "find references" work correctly again.
 
 
 v4.5.0