Added compressed font

[OlegSirenko]

Hi! I working with ImGui for creating the Portable application. I need to use the minimum number of dependencies in the final application directory. So I decided to add the ability to use a compressed font with ImGuiNotify. I think it will be useful not only for me. I left a couple of links with guides on how to create and use compressed fonts.
To make it clear exactly how I created the compressed font:

1. Download the binary_to_compressed_c.cpp
2. Cd to fonts directory (from the example's root):

cd fonts

3. On linux use g++ to build the executable:

g++ binary_to_compressed_c.cpp

4. Then run executable:

./a.out ./fa-solid-900.ttf fa_solid_900 > fa-solid-900.h

To use this font with ImGuiNotify:

1. Include the header file of compressed font in the main.cpp

 #include "./fonts/fa-solid-900.h"

2. Use the fa_solid_900 compressed font in ImGui:

io.Fonts->AddFontDefault();

float baseFontSize = 16.0f;
float iconFontSize = baseFontSize * 2.0f / 3.0f; // FontAwesome fonts need to have their sizes reduced by 2.0f/3.0f in order to align correctly

static constexpr ImWchar iconsRanges[] = {ICON_MIN_FA, ICON_MAX_16_FA, 0}; // changed to constexpr (common practices)
ImFontConfig iconsConfig;
iconsConfig.MergeMode = true;
iconsConfig.PixelSnapH = true;
iconsConfig.GlyphMinAdvanceX = iconFontSize;
io.Fonts->AddFontFromMemoryCompressedTTF(fa_solid_900_compressed_data, fa_solid_900_compressed_size, iconFontSize, &iconsConfig, iconsRanges);

Hope this would be helpful