[lld] [lld/ELF] Add documentation on large sections (PR #82560)

[Fangrui Song via llvm-commits]

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@@ -169,4 +169,5 @@ document soon.
    ELF/linker_script
    ELF/start-stop-gc
    ELF/warn_backrefs
+   ELF/large_sections
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MaskRay wrote:

sort

https://github.com/llvm/llvm-project/pull/82560