compliance: #27 - more readme notes.

 On branch dev/next-release
 Your branch is ahead of 'origin/dev/next-release' by 3 commits.
   (use "git push" to publish your local commits)

 Changes to be committed:
	modified:   tests/compliance/README.md

 Changes not staged for commit:
	modified:   extern/riscv-compliance (modified content)
	modified:   extern/riscv-gnu-toolchain (modified content, untracked content)
	modified:   extern/riscv-isa-sim (modified content)
	modified:   extern/sail-riscv (modified content, untracked content)