Forking FLOSS project; where to put credits?

[stahta01]

I am forking an old version of GCC to build a cross compiler under Windows Msys2 Mingw environment. Likely GCC version 4.3.6.

Where do I put the credits for the work done by other on the cross compiler. The target hardware is the old Motorola 6809 8 bit CPU.

I was thinking in a file called CREDITS or credits.txt any better suggestions?

Tim S.