[Build] Drop 32bit support

bin/README.txt

@@ -3,13 +3,11 @@ Folder contains libraries used by the binding.
 Provide 'imgui.library.path' VM option to the folder with one of those file (ex: -Dimgui.library.path=./some/folder).
 In the same way you can use 'java.library.path' option instead.
 
-By default binding expects 'imgui-java' ('imgui-java64' for x64 arch) file name.
+By default binding expects 'imgui-java64' file name.
 You can change that by using 'imgui.library.name' VM option (ex: -Dimgui.library.name=custom-lib-name).
 
-- imgui-java.dll        << Windows 32bit
-- imgui-java64.dll      << Windows 64bit
-- libimgui-java.so      << Linux 32bit
-- libimgui-java64.so    << Linux 64bit
+- imgui-java64.dll      << Windows
+- libimgui-java64.so    << Linux
 - libimgui-java64.dylib << MacOS
 
 Freetype folder contains same libraries, but with Freetype support.