[lld] Convert CODE_OWNERS.txt to Maintainers.md (#118084)

To align with https://llvm.org/docs/DeveloperPolicy.html#maintainers

I've moved the file and changed it to markdown to match `llvm/`'s file.

Author: DavidSpickett

lld/CODE_OWNERS.TXT

@@ -0,0 +1,40 @@
+# LLD Maintainers
+
+This file is a list of the
+[maintainers](https://llvm.org/docs/DeveloperPolicy.html#maintainers) for
+LLD.
+
+## Current Maintainers
+
+The following people are the active maintainers for the project. Please reach
+out to them for code reviews, questions about their area of expertise, or other
+assistance.
+
+### COFF, ELF backends (COFF/* ELF/*)
+
+Rui Ueyama \
+[email protected] (email)
+
+### Old Mach-O backend
+
+Lang Hames \
+[email protected] (email)
+
+Nick Kledzik \
+[email protected] (email)
+
+### WebAssembly backend (wasm/*)
+
+Sam Clegg \
+[email protected] (email)
+
+### New Mach-O backend
+
+Jez Ng \
+[email protected] (email)
+
+Greg McGary \
+[email protected] (email)
+
+Shoaib Meenai \
+[email protected] (email)

lld/Maintainers.md

@@ -434,7 +434,7 @@ Others only have a lead maintainer listed here.
 
 [Flang maintainers](https://github.com/llvm/llvm-project/blob/main/flang/Maintainers.txt)
 
-[LLD maintainers](https://github.com/llvm/llvm-project/blob/main/lld/CODE_OWNERS.TXT)
+[LLD maintainers](https://github.com/llvm/llvm-project/blob/main/lld/Maintainers.md)
 
 [LLDB maintainers](https://github.com/llvm/llvm-project/blob/main/lldb/Maintainers.rst)