ring-to-awslc.md

Migrate from ring to aws_lc_rs

rg -l 'ring::' --glob '*.rs' | xargs -I{} perl -pi -e 's/\bring::/aws_lc_rs::/g' {}
rg -l --fixed-strings 'ring.workspace' --glob '*.toml' \
  | xargs -I{} perl -pi -e 's/\bring\.workspace\b/aws-lc-rs.workspace/g' {}