docs: credit Konrad EISELE for the initial multilib support

Konrad submitted an initial patch adding multlib support:
http://sourceware.org/ml/crossgcc/2011-11/msg00040.html

The patch was full of good ideas, but had a few issues, so
I (Yann E. MORIN) started it all from scatch, re-using part
of the original patch. This got implemented in this series:
hg log -r 446a17b5dd1e:e47d17391ae3

As I forgot to credit Konrad in these changelogs, update the
docs so that the work by Konrad gets credited. Without his
initial effort, we would probably not have had multlib support
so soon. Thank you Konrad!

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

# mingw32 config options

## depends on EXPERIMENTAL && ( ARCH_x86 && ARCH_32 )

##

## select MINGW32

##

## help Build a toolchain targeting systems running Windows as host

choice

    bool

    prompt "Windows api version"

# Don't remove next line

# CT_INSERT_VERSION_BELOW

config W32API_V_3_14

    bool

    prompt "3.14"

config W32API_V_select

    bool

    prompt "Other version"

endchoice

config W32API_VERSION

    string

    prompt "W32 api version" if W32API_V_select

# Don't remove next line

# CT_INSERT_VERSION_STRING_BELOW

    default "3.14" if W32API_V_3_14

    help

      Enter the version number of the windows api files to use