Set clang-format macro indent.

1) Set clang-format macro indent.
2) Run clang-format on every files.

include/ftxui/screen/string.hpp

@@ -6,7 +6,7 @@
 std::string to_string(const std::wstring& s);
 std::wstring to_wstring(const std::string& s);
 
-template<typename T>
+template <typename T>
 std::wstring to_wstring(T s) {
   return to_wstring(std::to_string(s));
 }