improvements to example project file topic

Author: mikeblome

docs/ide/project-files.md

@@ -1,19 +1,19 @@
 ---
-title: "Project Files | Microsoft Docs"
+title: "Example Project File | Microsoft Docs"
 ms.custom: ""
-ms.date: "11/04/2016"
+ms.date: "10/09/2018"
 ms.technology: ["cpp-ide"]
 ms.topic: "conceptual"
 dev_langs: ["C++"]
-helpviewer_keywords: [".vcproj files", "Visual C++ projects, project file format", "VCPROJ (Visual C++ project file) format", "project files [C++], .vcproj file format"]
+helpviewer_keywords: [".vcxproj files", "C++ projects, project file format"]
 ms.assetid: 5261cf45-3136-40a6-899e-dc1339551401
 author: "corob-msft"
 ms.author: "corob"
 ms.workload: ["cplusplus"]
 ---
 # Project Files
 
-A Visual C++ project file is an XML-based file that has the .vcxproj file name extension and contains information that is required to build a Visual C++ project.
+A Visual C++ project file is an XML-based file that has the .vcxproj file name extension and contains information that is required to build a Visual C++ project. Note that the project file imports various project files that have the extension *.props* or *.targets*. These files contain additional build information, and might themselves refer to other *.props* or *.targets* files. The macros in the file path (for example `$(VCTargetsPath)`) are dependent on your Visual Studio installation. For more information about these macros and *.props* and *.targets* files, see [VC++ Directories Property Page](vcpp-directories-property-page.md), [Working with Project Properties](working-with-project-properties.md#bkmkPropertiesVersusMacros) and [Common Macros for Build Commands and Properties](common-macros-for-build-commands-and-properties.md).
 
 ## Example
 

docs/ide/vcpp-directories-property-page.md

@@ -1,7 +1,7 @@
 ---
 title: "VC++ Directories Property Page | Microsoft Docs"
 ms.custom: ""
-ms.date: "04/26/2018"
+ms.date: "10/09/2018"
 ms.technology: ["cpp-ide"]
 ms.topic: "conceptual"
 f1_keywords: ["VC.Project.VCDirectories.IncludePath", "VC.Project.VCDirectories.ReferencePath", "VC.Project.VCDirectories.SourcePath", "VC.Project.VCDirectories.LibraryWPath", "VC.Project.VCDirectories.ExecutablePath", "VC.Project.VCDirectories.LibraryPath", "VS.ToolsOptionsPages.Projects.VCDirectories", "VC.Project.VCDirectories.ExcludePath"]
@@ -58,7 +58,7 @@ Note: The list is populated as you type. Don't press **Enter**.
 
 For more information about macros and why you should use them instead of hard-coded paths whenever possible, see [Working with Project Properties](../ide/working-with-project-properties.md#bkmkPropertiesVersusMacros).
 
-For a list of commonly used macros, see [Common Macros for Build Commands and Properties](https://docs.microsoft.com/cpp/ide/common-macros-for-build-commands-and-properties).
+For a list of commonly used macros, see [Common Macros for Build Commands and Properties](common-macros-for-build-commands-and-properties.md).
 
 You can define your own macros in two ways: