Add Blink. Refactor examples.

examples/dom/separator.cpp

@@ -0,0 +1,25 @@
+#include "ftxui/screen.hpp"
+#include "ftxui/dom/elements.hpp"
+#include <iostream>
+
+int main(int argc, const char *argv[])
+{
+  using namespace ftxui::dom;
+  auto document =
+    hbox(
+      text(L"left-column"),
+      separator(),
+      flex(vbox(
+        flex(center(text(L"right-column"))),
+        separator(),
+        center(text(L"bottom-column"))
+      ))
+    );
+  auto screen = ftxui::Screen::TerminalFullscreen();
+  Render(screen, document.get());
+
+  std::cout << screen.ToString();
+  getchar();
+
+  return 0;
+}