pypi description now uses markdown from README.md

fixed incorrect usage instructions

 ## Added

- pypi readme
- installation instructions in more detail for cases where an updated
version is not found

 ## Fixed

- incorrect usage instructions. i3 needs a full path to the
polybar-reload in the case of zsh users. i3 uses sh to execute commands
following the exec directive. zsh users usually don't add ~/.local/bin
to PATH in bashrc, which is what is sourced for sh. So instead of going
into details for different shell users in the readme i've opted for
people to just use a full path. works with all shells and the install
directory is always ~/.local/bin

Added documentation, switched to ipc protocol

 ## Added

- now restarts polybar via ipc, which is faster and more idiomatic
- added usage documentation

added missing binary in setup.py

should now function as a script

 ## Changed

- should now work as a script you can call in the terminal, and should be added
  to PATH on install

 ## Fixed

- setup.py now correctly specifies this package is compatible only with python 3

Added missing dependencies, and added standard files

 ## Added
- now including an __init__.py, still need to add contents to it
- .gitignore

 ## Fixed
- project now specifies it's dependencies so that they're download as part of install

added download_url to setup.py