[llvm] [docs] Replace llvm.org/docs links with project links (PR #222506)

[Reid Kleckner via llvm-commits]

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@@ -217,8 +217,8 @@ compiling a **fixed source** with **differing compilers** or
 **differing optimization settings**.
 
 {program}`llvm-remarkutil size-diff` handles both
-[YAML](https://llvm.org/docs/Remarks.html#yaml-remarks) and
-[bitstream](https://llvm.org/docs/Remarks.html#llvm-bitstream-remarks)
+[YAML](project:../Remarks.md#yaml-remarks) and
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rnk wrote:

After thinking about it for a few days, I think the project: prefix really is the way to go. Otherwise it's ambiguous whether you are referring to relative paths in the generated HTML (path:) or relative paths in the docutils source tree (rst/md files). I've seen examples of [link](Target.html#slug) that work, but Sphinx doesn't do the translation, it's just a plain relative href, so you get less error checking.

https://github.com/llvm/llvm-project/pull/222506