Update readme and building_for_windows

Adds links to programs needed in the windows file and links to
CONTRIBUTING.md for both Windows and Linux.

docs/building_for_windows.md

@@ -4,6 +4,7 @@
  > * [Requirements](#requirements)
  > * [Locations and Environment Variables](#locs_and_envs)
  > * [Building](#features)
+ > * [Contributing](#contributing)
  > * [Using with QtCreator](#qt_creator)
  > * [Using with Visual Studio](#visual_studio)
 
@@ -12,12 +13,18 @@
 
 For compiling:
 
-1. Microsoft Visual Studio (tested on 2017 Community)
-2. Qt Framework (tested on 5.10 and 5.11)
+1. [Microsoft Visual Studio](https://visualstudio.microsoft.com/downloads/) (tested on 2017 Community)
+2. [Qt Framework](https://www.qt.io/download) version later than 5.6 (tested on 5.10 and 5.11)
+
+For pushing changes to the repo:
+
+1. [Python 3](https://www.python.org/downloads/) (must be in `PATH` environment variable)
+
+2. Clang format. Part of the [LLVM collection](https://releases.llvm.org/download.html).
 
 Additionally, for fully building portable and installer release versions:
-3. 7zip
-4. Nullsoft Scriptable Install System (NSIS)
+3. [7zip](https://www.7-zip.org/download.html)
+4. [Nullsoft Scriptable Install System (NSIS)](https://sourceforge.net/projects/nsis/)
 
 <a name="locs_and_envs"></a>
 ## Locations and Environment Variables
@@ -28,9 +35,10 @@ The following environmental variables are relevant for building the project.
 | --------------------  | ------------- |
 | `QT_LOC`              | Path to your Qt `\bin\` folder.    |
 | `VS_LOC`              | Path to your Visual Studio `vcvarsall.bat` file.  |
-| `JOM_LOC`             | Path to an `.exe` of `jom.exe`. Usually installed with Qt. `jom` is a wrapper around `nmake` allowing more threads to be used. It is not required, but using `nmake`is slower. If `JOM_LOC` isn't defined, or the `.exe` can't be found `nmake` will be used by default.   |
+| `JOM_LOC`             | Path to an `.exe` of `jom.exe`. Usually installed with Qt. `jom` is a wrapper around `nmake` allowing more threads to be used. It is not required, but using `nmake`is slower. If `JOM_LOC` isn't defined, or the `.exe` can't be found `nmake` will be used by default. To force using `nmake`, set `JOM_LOC` to a non-valid path like `1`.  |
 | `ZIP_LOC`             | Path to your 7zip `.exe`. Both portable and installer will work.  |
 | `NSIS_LOC`            | Path to your installation of NSIS containing the `makensis` file. Both portable and installer will work. |
+| `CLANG_FORMAT_LOC`            | Path to your `clang-format.exe`. Not necessary for building, but necessary for pushing changes to the repo. |
 
 If an environment variable isn't set a default value will be provided. The default values are shown in the table below.
 
@@ -41,6 +49,7 @@ If an environment variable isn't set a default value will be provided. The defau
 | `JOM_LOC`             | `"C:\Qt\Tools\QtCreator\bin\jom.exe"`|
 | `ZIP_LOC`             | `"C:\Program Files\7-Zip\7z.exe"`    |
 | `NSIS_LOC`            | `"C:\Program Files (x86)\NSIS\"`     |
+| `CLANG_FORMAT_LOC`            | `"C:\Program Files\LLVM\bin\clang-format.exe"`     |
 
 Additionally, these optional environment variables are supported.
 
@@ -58,6 +67,11 @@ The `.dll` files necessary for a release build differ from those needed by a deb
 
 With the programs above installed and environment variables set, go into the root folder of the repository and run `build_windows.cmd`. Compiled binaries along with everything needed to run portable will output to `.\bin\win64\AdvancedSettings\`.
 
+<a name="contributing"></a>
+## Contributing
+
+For full details, see [CONTRIBUTING.md](docs/CONTRIBUTING.md).
+
 <a name="qt_creator"></a>
 ## Using with QtCreator