Tweaked cmake-subproject section for clarity.

doc/cmake.dox

@@ -65,16 +65,16 @@ separate them with semicolons.
 
 @section cmake-subproject Using Magnum as a CMake subproject
 
-A self-contained alternative to the above is adding Corrade and Magnum
+A self-contained alternative to a shared instance of the libraries, is
-repositories into your project (as a Git submodule, bundling a downloaded
+to add the repositories directly into your project (as Git submodules, bundling
-archive etc.) and use @cb{.cmake} add_subdirectory() @ce. With that approach
+downloaded archives etc.), and then to use Cmake's @cb{.cmake} add_subdirectory() @ce
-you don't need to care about `FindCorrade.cmake` / `FindMagnum.cmake`, however
+feature to compile them on demand. With this approach, you don't need to care about
-the usual tradeoffs when bundling code apply --- slower full rebuilds, IDEs
+manually installing Magnum and Corrade, however the usual tradeoffs
-having more to parse etc. In this case, the
+when bundling code apply --- slower full rebuilds, IDEs having more to parse etc.
-@ref building-features "build-time options" are @cmake set() @ce before
+In this case, @ref building-features "build-time options" can be @cmake set() @ce
-the @cmake add_subdirectory() @ce call. Note that, unless you require CMake
+before calling @cmake add_subdirectory() @ce .
-3.13 at least, it's needed to use the `CACHE ... FORCE` arguments
+Note that, unless you require CMake 3.13 at least, it's necessary to use the `CACHE ... FORCE`
-[in order to have the options set properly](https://cmake.org/cmake/help/latest/policy/CMP0077.html). For example:
+arguments [in order to have the options set properly](https://cmake.org/cmake/help/latest/policy/CMP0077.html). For example:
 
 @code{.cmake}
 add_subdirectory(corrade EXCLUDE_FROM_ALL) # so only things you use are built
@@ -85,7 +85,9 @@ add_subdirectory(magnum EXCLUDE_FROM_ALL)
 find_package(Magnum REQUIRED ...) # see below
 @endcode
 
-Note that the @cb{.cmake} find_package() @ce call is needed in both the
+Note that the use of @cb{.cmake} add_subdirectory() @ce does not replace
+the configuration necessary for an installed version of magnum.
+The modules directory and calls to @cb{.cmake} find_package() @ce are needed in both the
 installed and the subproject case for a properly configured environment.
 
 To simplify your project setup, the subproject globally configures