Expose HarfBuzz 3.3 APIs, attempt 2.

Documentation-compilation fixes, release v1!

Document shaping & version-number APIs!

Fix segfaults & include test assets (major refactor).

Finalize release 0.1!

Fix segfault upon too much HarfBuzz concurrency.

Fix reentrancy complaints from GHC, attempt to fix segfault.

Add documentation & corrected type signatures.

Add, test, & fix shaping function.

Draft pure-functional Harfbuzz API.