Add clang-format config file.

.clang-format

diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..ae7dcb5
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,9 @@
+BasedOnStyle: LLVM
+IndentWidth: 4
+ColumnLimit: 2000
+AlwaysBreakAfterReturnType: TopLevelDefinitions
+KeepEmptyLinesAtTheStartOfBlocks: false
+MaxEmptyLinesToKeep: 2
+BreakBeforeBraces: Custom
+BraceWrapping:
+  BeforeElse: true