FAQ/install: further adjustments to OS X SIP FAQs

closes commercialhaskell#1799

doc/faq.md

@@ -296,7 +296,7 @@ These are written to `*.dump-*` files inside the package's `.stack-work` directo
 
 <a name="dyld-library-path-ignored"></a>If you
 are on Mac OS X 10.11 ("El Capitan") or later, there are upstream issues which
-[prevents the `DYLD_LIBRARY_PATH` environment variable from being passed to GHC](https://github.com/commercialhaskell/stack/issues/1161)
+[prevent the `DYLD_LIBRARY_PATH` environment variable from being passed to GHC](https://github.com/commercialhaskell/stack/issues/1161)
 when System Integrity Protection (a.k.a. "rootless") is enabled. The only
 workaround we are aware of is
 [disabling System Integrity Protection](http://osxdaily.com/2015/10/05/disable-rootless-system-integrity-protection-mac-os-x/).

doc/install_and_upgrade.md

@@ -54,12 +54,6 @@ such.
 
 ## Mac OS X
 
-Note: if you are on OS X 10.11 ("El Capitan") and encounter either of these
-problems, see the linked FAQ entries.
-
-  * [GHC 7.8.4 fails with `/usr/bin/ar: permission denied`](faq.html#usr-bin-ar-permission-denied)
-  * [DYLD_LIBRARY_PATH is ignored](faq.html#dyld-library-path-ignored)
-
 ### Using Homebrew
 
 If you have a popular [brew](http://brew.sh/) tool installed, you can just do:
@@ -87,6 +81,15 @@ will take hours), see
 We generally test on the current version of Mac OS X, but stack is known to work on
 Yosemite and Mavericks as well, and may also work on older versions (YMMV).
 
+### Notes
+
+If you are on OS X 10.11 ("El Capitan") and encounter either of these
+problems, see the linked FAQ entries:
+
+  * [GHC 7.8.4 fails with `/usr/bin/ar: permission denied`](faq.html#usr-bin-ar-permission-denied)
+  * [DYLD_LIBRARY_PATH is ignored](faq.html#dyld-library-path-ignored)
+
+
 ## Ubuntu
 
 *note*: for 32-bit, use the [generic Linux option](#linux)