[libc++] Update contributor documentation.
authorMark de Wever <koraq@xs4all.nl>
Wed, 24 Mar 2021 18:54:40 +0000 (19:54 +0100)
committerMark de Wever <koraq@xs4all.nl>
Wed, 7 Apr 2021 16:33:27 +0000 (18:33 +0200)
commit48fa06f70b07fc195a07bfb67ee42cfd307ca450
treec82c2da5363e398b2f01d09a92e3bee33899fcd4
parent1894c6c59e37b47c284f2a5ebb92b73911e71e38
[libc++] Update contributor documentation.

The document has the following updates:
- Rename 'feature test' to 'feature-test', the latter is the spelling
  used in the Standard.
- Add information how an ABI list can be downloaded from Buildkite.

Differential Revision: https://reviews.llvm.org/D99290
libcxx/docs/Contributing.rst