Use fbsource clang-format config

Summary:
This mirrors the clang-format config used by fbsource to Yoga.

They are pretty similar, except for an annoying habit where Yoga's previous forced small functions in headers to be a a single line, so you would get a combination of multiline and single line functions next to each other which are hard to read. That is what motivated this change.

It also enforces header ordering (yay). I don't think we have any side-effect causing headers, so this should be safe.

Reviewed By: yungsters

Differential Revision: D49248994

fbshipit-source-id: 66998395e7c0158ff9d9fb1bee44e8401bdd8f21

tests/YGHadOverflowTest.cpp

@@ -11,7 +11,7 @@
 using namespace ::testing;
 
 class YogaTest_HadOverflowTests : public Test {
-protected:
+ protected:
   YogaTest_HadOverflowTests() {
     config = YGConfigNew();
     root = YGNodeNewWithConfig(config);