add intro

docs/index.rst

 Remix - Solidity IDE
 ====================
 
+Remix is an Solidity IDE. 
+It allows developing / debugging Solidity smart contract.
+
+An online version is accessible at `remix.ethereum.org <http://remix.ethereum.org>`_
+
+This page will host documentation and tutorial about features Remix provides.
+
+Please browse `solidity.readthedocs.io <http://solidity.readthedocs.io>`_ for any information regarding ``Solidity``
+
 Tutorial
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