add link to vs build tools

docs/building.md

@@ -42,7 +42,7 @@ Notes:
 
 ### Windows
 
-The windows build only supports the Visual Studio compiler (for now). You can download Visual Studio Community 2019 [here](https://visualstudio.microsoft.com/downloads/). Be sure to install the "Desktop development with C++" component.
+The windows build only supports the Visual Studio compiler (for now). To get the compiler, download and install the Visual Studio 2019 Build Tools [here](https://visualstudio.microsoft.com/downloads/#build-tools-for-visual-studio-2019). If you want to instead use the full Visual Studio, you can download IDE Visual Studio Community 2019 [here](https://visualstudio.microsoft.com/downloads/). Be sure to install the "Desktop development with C++" component.
 
 You can download CMake for windows [here](https://cmake.org/download/).
 

docs/pathtracer/overview.md

@@ -19,7 +19,6 @@ Implementing the functionality of PathTracer is split in to 7 tasks, and here ar
 - [(Task 6) Materials](materials.md)
 - [(Task 7) Environment Lighting](environment_lighting.md)
 
-
 The files that you will work with for PathTracer are all under `src/student` directory. Some of the particularly important ones are outlined below. Methods that we expect you to implement are marked with "TODO (PathTracer)", which you may search for.
 
 | File(s)  |      Purpose      |  Need to modify? |