[skip ci] updated README

Author: tclose

README.rst

@@ -1,5 +1,83 @@
 Nipype2Pydra
 ============
+.. image:: https://github.com/nipype/nipype2pydra/actions/workflows/tests.yml/badge.svg
+   :target: https://github.com/nipype/nipype2pydra/actions/workflows/tests.yml
+.. image:: https://codecov.io/gh/nipype/nipype2pydra/branch/main/graph/badge.svg?token=UIS0OGPST7
+   :target: https://codecov.io/gh/nipype/nipype2pydra
+.. image:: https://img.shields.io/pypi/pyversions/nipype2pydra.svg
+   :target: https://pypi.python.org/pypi/nipype2pydra/
+   :alt: Supported Python versions
+.. image:: https://img.shields.io/pypi/v/nipype2pydra.svg
+   :target: https://pypi.python.org/pypi/nipype2pydra/
+   :alt: Latest Version
 
-CLI tool for porting Nipype code to Pydra
+Nipype2Pydra is a command-line tool for semi-automatically porting command interfaces
+and workflows written from the Nipype_ workflow engine to its successor Pydra_. It has
+been designed so that any required manual-specifications are stored in separate YAML
+specification files, which is read ahead of the conversion, so once designed the
+conversion can be re-run to pick up changes in newer versions of the Nipype_ code without
+having to redo the manual steps.
 
+
+Basic Usage
+-----------
+
+To convert a Nipype_ interface to a Pydra_ task run the `nipype2pydra task` command and
+pass it the conversion specification YAML file and the root of the package to save the
+generated module, e.g.::
+
+    $ nipype2pydra task ants_registration_registration.yaml /Users/youruser/git/pydra-ants/
+
+
+Conversion Specifications
+-------------------------
+
+While the conversions aim to as automatic as possible, there are structural
+differences between Nipype_ and Pydra_ that require manual specification, and it might
+be desirable to rename some of the inputs/outputs to more intuitive names. Such
+specifications are stored in YAML_ format, such as the ANTs registration conversion
+specification,
+
+.. code-block::yaml
+
+    task_name: Registration
+    nipype_module: nipype.interfaces.ants.registration
+    output_requirements:
+        output_warped_image: ["fixed_image", "moving_image", "output_transform_prefix"]
+    output_templates:
+        output_warped_image: "{output_transform_prefix}warped"
+    doctest:
+        fixed_image: test.nii.gz
+        moving_image: test.nii.gz
+        cmdline: >- 
+            antsRegistration --output [ output_, output_warped_image.nii.gz ]
+            --metric Mattes[ test.nii, test.nii, 1, 32, Random, 0.05 ]
+        tests_inputs: []
+        tests_outputs:
+        - AttributeError
+
+*Detailed description of the different options to go here*
+
+Installation
+------------
+
+*Nipype2Pydra* can be installed for Python >= 3.7 from PyPI with
+
+.. code-block:: bash
+
+    $ python3 -m pip nipype2pydra
+
+
+License
+-------
+
+This work is licensed under a
+`Creative Commons Attribution 4.0 International License <http://creativecommons.org/licenses/by/4.0/>`_
+
+.. image:: https://i.creativecommons.org/l/by/4.0/88x31.png
+  :target: http://creativecommons.org/licenses/by/4.0/
+  :alt: Creative Commons Attribution 4.0 International License
+
+.. _Pydra: https://pydra.readthedocs.io
+.. _Nipype: https://nipype.readthedocs.io/en/latest/
+.. _YAML: https://yaml.org