🔨 AppVeyor: Use system (vcpkg) fmt

appveyor.yml

@@ -6,7 +6,7 @@ image: Visual Studio 2017
 cache: c:\tools\vcpkg\installed\
 
 install:
-  - vcpkg install sdl2:x64-windows sdl2-mixer:x64-windows sdl2-ttf:x64-windows libsodium:x64-windows
+  - vcpkg install fmt:x64-windows sdl2:x64-windows sdl2-mixer:x64-windows sdl2-ttf:x64-windows libsodium:x64-windows
 
 before_build:
   - cmake -G "Visual Studio 15 2017" -A x64 -DNIGHTLY_BUILD=ON -DCMAKE_TOOLCHAIN_FILE=c:/tools/vcpkg/scripts/buildsystems/vcpkg.cmake .

docs/building.md

@@ -126,13 +126,13 @@ Make sure to install the `C++ CMake tools for Windows` component for Visual Stud
    For the 64-bit version of the dependencies please run this command:
 
    ```
-   vcpkg install sdl2:x64-windows sdl2-mixer:x64-windows sdl2-ttf:x64-windows libsodium:x64-windows gtest:x64-windows
+   vcpkg install fmt:x64-windows sdl2:x64-windows sdl2-mixer:x64-windows sdl2-ttf:x64-windows libsodium:x64-windows gtest:x64-windows
    ```
 
    For the 32-bit version of the dependencies please run this command:
 
    ```
-   vcpkg install sdl2:x86-windows sdl2-mixer:x86-windows sdl2-ttf:x86-windows libsodium:x86-windows gtest:x86-windows
+   vcpkg install fmt:x86-windows sdl2:x86-windows sdl2-mixer:x86-windows sdl2-ttf:x86-windows libsodium:x86-windows gtest:x86-windows
    ```
 
 * **Manually**