[clang-tools-extra] reapply [clang-doc] Add --asset option to clang-doc (PR #96358)

[Paul Kirth via cfe-commits]

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@@ -25,7 +25,7 @@ set(assets
 )
 
 set(asset_dir "${CMAKE_CURRENT_SOURCE_DIR}/../assets")
-set(resource_dir "${CMAKE_BINARY_DIR}/share/clang")
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ilovepi wrote:

Can we do this updating in a standalone patch? Same for the other places where you've updated the path.

https://github.com/llvm/llvm-project/pull/96358