update dev docs to also say macOS and use openssl 1.1 (#3452)

diff --git a/docs/development/getting-started.rst b/docs/development/getting-started.rst
index d94e656..29d01c3 100644
--- a/docs/development/getting-started.rst
+++ b/docs/development/getting-started.rst
@@ -30,8 +30,8 @@
 
 You are now ready to run the tests and build the documentation.
 
-OpenSSL on OS X
-~~~~~~~~~~~~~~~
+OpenSSL on macOS
+~~~~~~~~~~~~~~~~
 
 You must have installed `OpenSSL`_ via `Homebrew`_ or `MacPorts`_ and must set
 ``CFLAGS`` and ``LDFLAGS`` environment variables before installing the
@@ -41,8 +41,8 @@
 
 .. code-block:: console
 
-    $ env LDFLAGS="-L$(brew --prefix openssl)/lib" \
-        CFLAGS="-I$(brew --prefix openssl)/include" \
+    $ env LDFLAGS="-L$(brew --prefix openssl@1.1)/lib" \
+        CFLAGS="-I$(brew --prefix openssl@1.1)/include" \
         pip install --requirement ./dev-requirements.txt
 
 Alternatively for a static build you can specify