Update head doc (#1127)

* update head doc

* update head doc

Author: AtsushiSakai

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2016 - 2022 Atsushi Sakai and other contributors:
+Copyright (c) 2016 - now Atsushi Sakai and other contributors:
 https://github.com/AtsushiSakai/PythonRobotics/contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy

docs/getting_started_main.rst

@@ -3,11 +3,15 @@
 Getting Started
 ===============
 
-What is this?
--------------
+.. _`What is PythonRobotics?`:
+
+What is PythonRobotics?
+------------------------
 
 This is an Open Source Software (OSS) project: PythonRobotics, which is a Python code collection of robotics algorithms.
 
+This is developped under `MIT license`_ and on `GitHub`_.
+
 The focus of the project is on autonomous navigation, and the goal is for beginners in robotics to understand the basic ideas behind each algorithm.
 
 In this project, the algorithms which are practical and widely used in both academia and industry are selected.
@@ -16,6 +20,17 @@ Each sample code is written in Python3 and only depends on some standard modules
 
 It includes intuitive animations to understand the behavior of the simulation.
 
+.. _GitHub: https://github.com/AtsushiSakai/PythonRobotics
+.. _`MIT license`: https://github.com/AtsushiSakai/PythonRobotics/blob/master/LICENSE
+
+Features:
+
+1. Easy to read for understanding each algorithm's basic idea.
+
+2. Widely used and practical algorithms are selected.
+
+3. Minimum dependency.
+
 
 See this paper for more details:
 

docs/index_main.rst

@@ -6,32 +6,32 @@
 Welcome to PythonRobotics's documentation!
 ==========================================
 
-Python codes for robotics algorithm. The project is on `GitHub`_.
+"PythonRobotics" is a Python code collections and html based text book
+(This document) for robotics algorithm, which is developed on `GitHub`_.
 
-This is a Python code collection of robotics algorithms.
+See this section (:ref:`What is PythonRobotics?`) for more details of this project.
 
-Features:
+This project  is `the one of the most popular open-source software (OSS) in
+the field of robotics on GitHub`_.
+This is `user comments about this project`_, and
+this graph shows GitHub star history of this project:
 
-1. Easy to read for understanding each algorithm's basic idea.
+.. image:: https://api.star-history.com/svg?repos=AtsushiSakai/PythonRobotics&type=Date
+   :alt: Star History
+   :width: 80%
+   :align: center
 
-2. Widely used and practical algorithms are selected.
 
-3. Minimum dependency.
-
-See this paper for more details:
-
--  `[1808.10703] PythonRobotics: a Python code collection of robotics
-   algorithms`_ (`BibTeX`_)
-
-
-.. _`[1808.10703] PythonRobotics: a Python code collection of robotics algorithms`: https://arxiv.org/abs/1808.10703
-.. _BibTeX: https://github.com/AtsushiSakai/PythonRoboticsPaper/blob/master/python_robotics.bib
 .. _GitHub: https://github.com/AtsushiSakai/PythonRobotics
+.. _`user comments about this project`: https://github.com/AtsushiSakai/PythonRobotics/blob/master/users_comments.md
+.. _`MIT license`: https://github.com/AtsushiSakai/PythonRobotics/blob/master/LICENSE
+.. _`the one of the most popular open-source software (OSS) in the field of robotics on GitHub`: https://github.com/topics/robotics
 
+----------------------------------
 
 .. toctree::
    :maxdepth: 2
-   :caption: Contents
+   :caption: Table of Contents
 
    getting_started
    modules/1_introduction/introduction