Azure-shell

* add register.py and separate 'READM.md to rst conversion' logic from setup.py

* fixup bug in index_geenrator.py- [Issue 2](https://github.com/yokawasa/azure-shell/issues/2)

* fixup bug - [Issue 1](https://github.com/yokawasa/azure-shell/issues/1)

* [NOT Recommended] Please skip this version as it still has index loading issue while tried to fixup [Issue 1](https://github.com/yokawasa/azure-shell/issues/1)

* Added Index Generator executable (azure-shell-index-generator)

* Inital Release