Be on brand: it's macOS (#3456)

* Be on brand: it's macOS

* line wrap
diff --git a/docs/doing-a-release.rst b/docs/doing-a-release.rst
index 8e9222e..2da2c80 100644
--- a/docs/doing-a-release.rst
+++ b/docs/doing-a-release.rst
@@ -6,8 +6,8 @@
 Verifying and upgrading OpenSSL version
 ---------------------------------------
 
-The release process uses a static build for Windows and OS X wheels. Check that
-the Windows and OS X Jenkins builders have the latest version of OpenSSL
+The release process uses a static build for Windows and macOS wheels. Check
+that the Windows and macOS Jenkins builders have the latest version of OpenSSL
 installed before performing the release. If they do not:
 
 Upgrading Windows
@@ -16,8 +16,8 @@
 Run the ``openssl-release-1.1`` Jenkins job, then copy the resulting artifacts
 to the Windows builders and unzip them in the root of the file system.
 
-Upgrading OS X
-~~~~~~~~~~~~~~
+Upgrading macOS
+~~~~~~~~~~~~~~~
 
 ``brew update`` and then ``brew upgrade openssl@1.1 --build-bottle`` to
 install a 64-bit only library compatible with all Intel Macs.