Fix whitespace in doc

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@250238 91177308-0d34-0410-b5e6-96231b3b80d8

docs/DesignDocs/CapturingConfigInfo.rst

diff --git a/docs/DesignDocs/CapturingConfigInfo.rst b/docs/DesignDocs/CapturingConfigInfo.rst
index 0f16ca1..73378a2 100644
--- a/docs/DesignDocs/CapturingConfigInfo.rst
+++ b/docs/DesignDocs/CapturingConfigInfo.rst
@@ -49,7 +49,7 @@
 #defines. The contents of the dummy header are then prependend to the installed
 __config header. By manually prepending the files we avoid the cost of an
 extra #include and we allow the __config header to be ignorant of the extra
- configuration all together. An example "__config" header generated when
+configuration all together. An example "__config" header generated when
 -DLIBCXX_ENABLE_THREADS=OFF is given to CMake would look something like:
 
 .. code-block:: cpp