Update the png of nni_arch_overview (#473)

* update readme in ga_squad

* update readme

* fix typo

* Update README.md

* Update README.md

* Update README.md

* update readme

* update

* fix path

* update reference

* fix bug in config file

* update nni_arch_overview.png

* update

* update

* update

examples/trials/auto-gbdt/config.yml

@@ -18,4 +18,4 @@ tuner:
 trial:
   command: python3 main.py
   codeDir: .
-  gpuNum: 0
+  gpuNum: 0
\ No newline at end of file