Move old harfbuzz.org content to README.md Copied from: https://web.archive.org/web/20191221151847/https://freedesktop.org/wiki/Software/HarfBuzz/ Edited lightly trying to merge it with existing README.md content and remove grossly outdated bits. Might still need more editing. Fixes https://github.com/harfbuzz/harfbuzz/issues/1919