[Docs] Add CITATION.cff (open-mmlab#428)

* Add CITATION.cff

* Fix typo in setup.py

* Change author in setup.py

CITATION.cff

@@ -0,0 +1,9 @@
+cff-version: 1.2.0
+message: "If you use this software, please cite it as below."
+title: "OpenMMLab's Image Classification Toolbox and Benchmark"
+authors:
+  - name: "MMClassification Contributors"
+version: 0.15.0
+date-released: 2020-07-09
+repository-code: "https://github.com/open-mmlab/mmclassification"
+license: Apache-2.0

setup.py

@@ -95,7 +95,7 @@ def gen_packages_items():
     return packages
 
 
-def add_mim_extention():
+def add_mim_extension():
     """Add extra files that are required to support MIM into the package.
 
     These files will be added by creating a symlink to the originals if the
@@ -144,14 +144,14 @@ def add_mim_extention():
 
 
 if __name__ == '__main__':
-    add_mim_extention()
+    add_mim_extension()
     setup(
         name='mmcls',
         version=get_version(),
         description='OpenMMLab Image Classification Toolbox and Benchmark',
         long_description=readme(),
         long_description_content_type='text/markdown',
-        author='OpenMMLab',
+        author='MMClassification Contributors',
         author_email='openmmlab@gmail.com',
         keywords='computer vision, image classification',
         url='https://github.com/open-mmlab/mmclassification',