add README

.gitignore

+# Created by .ignore support plugin (hsz.mobi)
+.idea
+.idea/workspace.xml
+**/.ipynb_checkpoints
+.ipynb_checkpoints
+startup.py
+.python-version
+*.pyc
+*.pyc.orig
+.DS_Store
+

.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file