doc, windows: set LLVM_ENABLE_LIBEDIT=NO

Necessary to make the source compile. This option is used in the
current azure pipeline.

Author: patrickdes

docs/WindowsBuild.md

@@ -100,6 +100,7 @@ cmake -B "S:\b\toolchain" -G Ninja -S S:\toolchain\llvm ^
   -DLLVM_EXTERNAL_PROJECTS="cmark;swift" ^
   -DSWIFT_PATH_TO_LIBDISPATCH_SOURCE=S:\toolchain\swift-corelibs-libdispatch ^
   -DLLVM_ENABLE_PDB=YES ^
+  -DLLVM_ENABLE_LIBEDIT=NO ^
   -DLLDB_DISABLE_PYTHON=YES ^
   -DSWIFT_WINDOWS_x86_64_ICU_UC_INCLUDE="S:/Library/icu-64/usr/include" ^
   -DSWIFT_WINDOWS_x86_64_ICU_UC="S:/Library/icu-64/usr/lib/icuuc64.lib" ^