Merge branch 'master' into imporvedoc

Author: luomai

CONTRIBUTING.md

@@ -0,0 +1,13 @@
+# Contributing to TensorLayer
+
+We appreciate contributions towards TensorLayer 
+either by adding / improving examples or extending / fixing the TensorLayer core library. 
+To make your contributions, you would need to follow the guideline:
+we are using [pep8](https://www.python.org/dev/peps/pep-0008/) coding style and [numpy doc style](https://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt).
+The following tools are used to ensure that your PR comply the project convention:
+
+* yapf (format code)
+* isort (sort imports)
+* autoflake (remove unused imports)
+
+Please apply these tools in the changed files before submitting the PR.

README.md

@@ -231,7 +231,7 @@ We provide many helper functions (like `fit()` , `test()`) that is similar to Ke
 -->
 
 
-# Contributions
+# Community
 
 TensorLayer is maintained by numerous Github contributors [here](https://github.com/zsdonghao/tensorlayer/graphs/contributors). 
 This project is in an active development stage and has received numerous contributions from an open community. 
@@ -246,6 +246,12 @@ TensorLayer started as an internal repository at Imperial College London, helpin
 - 🇬🇧 If you have question, drop us an email: [email protected].
 - 🇨🇳 我们有官方的[中文文档](http://tensorlayercn.readthedocs.io/zh/latest), 另外我们建立了多种交流渠道, 如[QQ群](img/img_qq.png)和[微信群](https://github.com/shorxp/tensorlayer-chinese/blob/master/docs/wechat_group.md).
 
+
+# Contributions
+
+[Contributing guideline](./CONTRIBUTING.md)
+
+
 # Citation
 If you find it is useful, please cite our paper in your project and paper.