Help: Add missing word in CMAKE_CURRENT_{BINARY,SOURCE}_DIR

Help/variable/CMAKE_CURRENT_BINARY_DIR.rst

@@ -3,7 +3,7 @@ CMAKE_CURRENT_BINARY_DIR
 
 The path to the binary directory currently being processed.
 
-This the full path to the build directory that is currently being
+This is the full path to the build directory that is currently being
 processed by cmake.  Each directory added by :command:`add_subdirectory` will
 create a binary directory in the build tree, and as it is being
 processed this variable will be set.  For in-source builds this is the

Help/variable/CMAKE_CURRENT_SOURCE_DIR.rst

@@ -3,7 +3,7 @@ CMAKE_CURRENT_SOURCE_DIR
 
 The path to the source directory currently being processed.
 
-This the full path to the source directory that is currently being
+This is the full path to the source directory that is currently being
 processed by cmake.
 
 When run in -P script mode, CMake sets the variables