doc updates

- added RTD badge to README
- added placeholder DOI/zenodo badge to README (need to fix
  after making a pre-release)
- fixed sectioning in NAMD description
- removed "alpha warning" (see #25) from docs

README.rst

@@ -1,6 +1,8 @@
 alchemtest: the simple alchemistry test set
 ===========================================
 
+|doi| |docs|
+
 **alchemtest**  is a collection of test datasets for alchemical free energy calculations.
 The datasets come from a variety of software packages, primarily molecular
 dynamics engines, and are used as the test set for `alchemlyb`_.
@@ -15,3 +17,15 @@ modification, separation, for any purpose and without a charge.
 .. _`open license`:
    http://opendefinition.org/licenses/#recommended-conformant-licenses
 .. _`Open Definition 2.1`: http://opendefinition.org/od/2.1/en/
+
+
+.. |docs| image:: https://readthedocs.org/projects/alchemtest/badge/?version=latest
+    :alt: Documentation
+    :scale: 100%
+    :target: https://alchemtest.readthedocs.io/en/latest/
+
+.. |doi| image:: https://zenodo.org/badge/XXXXX.svg
+    :alt: Zenodo DOI
+    :scale: 100%
+    :target: https://zenodo.org/badge/latestdoi/XXXXX
+

docs/index.rst

@@ -13,17 +13,29 @@ package is standalone, however, and can be used for any purpose.
 
 Datasets are released under an `open license`_ that conforms to the `Open
 Definition 2.1`_ that allows free use, re-use, redistribution, modification,
-separation, for any purpose and without a charge.
+separation, for any purpose and without a charge. All data and code
+can be found in the public GitHub repository `alchemistry/alchemtest`_.
+
+This library is **under active development**. We use `semantic
+versioning`_ to indicate clearly what kind of changes you may expect
+between releases. Although it is heavily used for the alchemlyb_ test
+suite it may contain bugs. Please raise any issues or questions in the
+`Issue Tracker`_. `Contributions of data sets`_ and code in the form
+of pull requests are very welcome.
 
 
 .. _`alchemlyb`: https://github.com/alchemistry/alchemlyb
 .. _`open license`:
    http://opendefinition.org/licenses/#recommended-conformant-licenses
 .. _`Open Definition 2.1`: http://opendefinition.org/od/2.1/en/
-
-.. note:: This library is in an **alpha** state. The library and the
-          documentation is incomplete. Use in production at your own risk.
-
+.. _`alchemistry/alchemtest`:
+   https://github.com/alchemistry/alchemtest
+.. _`semantic versioning`: https://semver.org   
+.. _`Issue Tracker`:
+   https://github.com/alchemistry/alchemtest/issues
+.. _`Contributions of data sets`:
+   https://github.com/alchemistry/alchemtest/wiki/contributing
+
 
 .. toctree::
     :maxdepth: 1

src/alchemtest/namd/tyr2ala/descr.rst

@@ -1,6 +1,5 @@
-=======================================================================
- NAMD: free energy of tyrosine to alanine mutation in aqueous solution
-=======================================================================
+NAMD: free energy of tyrosine to alanine mutation in aqueous solution
+=====================================================================
 
 Free energy change from mutating a tyrosine (Y) residue into 
 alanine (A) in the Ala-Tyr-Ala tripeptide in aqueous environment.