ReleaseNotes: minor touch-ups

* Error message format has changed in order to improve readability.

  Traditionally, linker's error messages are concise and arguably too terse.

  This is an example of lld 4.0's error message (they are actually in one line)::

  This is an example of lld 4.0.0's error message (they are actually in one line)::

    /ssd/clang/bin/ld.lld: error: /ssd/llvm-project/lld/ELF/Writer.cpp:207:

      undefined symbol 'lld::elf::EhFrameSection::addSection()'

  It is not easy to read because too much information is packed into a single line

  and the embedded text, particularly a symbol name, is sometimes too long.

  In lld 5.0, we use more vertical space to print out error messages in a more

  In lld 5.0.0, we use more vertical space to print out error messages in a more

  structured manner like this::

    bin/ld.lld: error: undefined symbol: lld::elf::EhFrameSection::addSection()

  ``-z notext``, ``-z rodynamic``

COFF Improvements

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* Item 1.

Contributors to lld 5.0

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