[DOC] Use README as long_desc (#595)

* Use README as long_desc

* fix path handling

* since we're using pathlib... use it

tedana/info.py

@@ -4,6 +4,8 @@
 """
 Base module variables
 """
+from pathlib import Path
+readme_path = Path(__file__).parent.parent.joinpath("README.md")
 
 from ._version import get_versions
 __version__ = get_versions()['version']
@@ -21,7 +23,7 @@
 __packagename__ = 'tedana'
 __description__ = ('TE-Dependent Analysis (tedana) of multi-echo functional '
                    'magnetic resonance imaging (fMRI) data.')
-__longdesc__ = ('To do.')
+__longdesc__ = readme_path.open().read()
 
 DOWNLOAD_URL = (
     'https://github.com/ME-ICA/{name}/archive/{ver}.tar.gz'.format(