Update readme with ninja build

diff --git a/README.md b/README.md
index 575de845ee614ededfef606d4bc60926f51590de..72a61e568eb960cd8fd59eb2c562e6b7d3794d44 100644 (file)
--- a/README.md
+++ b/README.md
@@ -15,6 +15,14 @@ cmake ../
 make
 ```
 
+To build with ninja:
+```
+mkdir build
+cd build
+cmake -DCMAKE_BUILD_TYPE=Release -G Ninja ../
+ninja -v
+```
+
 # Contribute
 Use [OneFlow][3] branching model and keep the [changelog][4].