added licence file, readme, and updated .gitignore.

.gitignore

@@ -1,9 +1,4 @@
-*.png
-
-# Created by https://www.toptal.com/developers/gitignore/api/python
-# Edit at https://www.toptal.com/developers/gitignore?templates=python
-
-### Python ###
+# ---> Python
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]
@@ -26,7 +21,6 @@ parts/
 sdist/
 var/
 wheels/
-pip-wheel-metadata/
 share/python-wheels/
 *.egg-info/
 .installed.cfg
@@ -56,7 +50,7 @@ coverage.xml
 *.py,cover
 .hypothesis/
 .pytest_cache/
-pytestdebug.log
+cover/
 
 # Translations
 *.mo
@@ -77,9 +71,9 @@ instance/
 
 # Sphinx documentation
 docs/_build/
-doc/_build/
 
 # PyBuilder
+.pybuilder/
 target/
 
 # Jupyter Notebook
@@ -90,7 +84,9 @@ profile_default/
 ipython_config.py
 
 # pyenv
-.python-version
+#   For a library or package, you might want to ignore these files since the code is
+#   intended to run in multiple environments; otherwise, check them in:
+# .python-version
 
 # pipenv
 #   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
@@ -117,7 +113,6 @@ venv/
 ENV/
 env.bak/
 venv.bak/
-pythonenv*
 
 # Spyder project settings
 .spyderproject
@@ -140,7 +135,5 @@ dmypy.json
 # pytype static type analyzer
 .pytype/
 
-# profiling data
-.prof
-
-# End of https://www.toptal.com/developers/gitignore/api/python
+# Cython debug symbols
+cython_debug/