Remove legacy files and modernize README

Deleted:
- .hgignore, .hgtags (Mercurial remnants, repo is on git)
- buildout.cfg (zc.buildout config; replaced by uv)
- Makefile (referenced `python setup.py sdist upload`; had bogus path
  from another project; superseded by uv)
- INSTALL.txt (outdated: mentioned Python 2.3, `python setup.py install`,
  and codespeak lxml URL)

README.rst:
- Fixed Python 2 `print record` -> `print(record)`
- Updated CI badge to new workflow URL (mpasternak/pyoai)
- Added Python version support badge (3.10-3.13)
- Added modern installation instructions (pip, uv)
- Added development quickstart (uv sync, uv run pytest)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: mpasternak

.hgignore

@@ -1,35 +1,68 @@
 ======
-OAIPMH
+pyoai
 ======
 
 .. image:: https://img.shields.io/pypi/v/pyoai.svg
-        :target: https://pypi.python.org/pypi/pyoai
+    :target: https://pypi.python.org/pypi/pyoai
 
-.. image:: https://github.com/infrae/pyoai/workflows/Run%20tests/badge.svg
-    :target: https://github.com/infrae/pyoai/actions?query=workflow%3A%22Run+tests%22
-    
-The oaipmh module is a Python implementation of an "Open Archives
-Initiative Protocol for Metadata Harvesting" (version 2) client and
-server. The protocol is described here:
+.. image:: https://github.com/mpasternak/pyoai/actions/workflows/run_tests.yml/badge.svg
+    :target: https://github.com/mpasternak/pyoai/actions/workflows/run_tests.yml
 
-http://www.openarchives.org/OAI/openarchivesprotocol.html
+.. image:: https://img.shields.io/badge/python-3.10%20|%203.11%20|%203.12%20|%203.13-blue
+    :target: https://www.python.org/
 
-Below is a simple implementation of an OAIPMH client:
+The ``oaipmh`` module is a Python implementation of the
+`Open Archives Initiative Protocol for Metadata Harvesting`_ (version 2)
+client and server.
 
->>> from oaipmh.client import Client
->>> from oaipmh.metadata import MetadataRegistry, oai_dc_reader
+.. _Open Archives Initiative Protocol for Metadata Harvesting: http://www.openarchives.org/OAI/openarchivesprotocol.html
 
->>> URL = 'http://uni.edu/ir/oaipmh'
+Installation
+============
 
->>> registry = MetadataRegistry()
->>> registry.registerReader('oai_dc', oai_dc_reader)
->>> client = Client(URL, registry)
+.. code-block:: bash
 
->>> for record in client.listRecords(metadataPrefix='oai_dc'):
->>>    print record
+    pip install pyoai
 
+Or with `uv`_::
 
-The pyoai package also contains a generic server implementation of the 
-OAIPMH protocol, this is used as the foundation of the `MOAI Server Platform`_
+    uv add pyoai
 
-.. _MOAI Server Platform: http://pypi.python.org/pypi/MOAI
+.. _uv: https://docs.astral.sh/uv/
+
+Requirements
+============
+
+* Python 3.10+
+* `lxml <https://lxml.de/>`_
+
+Example
+=======
+
+A simple OAI-PMH client:
+
+.. code-block:: python
+
+    from oaipmh.client import Client
+    from oaipmh.metadata import MetadataRegistry, oai_dc_reader
+
+    URL = 'http://uni.edu/ir/oaipmh'
+
+    registry = MetadataRegistry()
+    registry.registerReader('oai_dc', oai_dc_reader)
+    client = Client(URL, registry)
+
+    for record in client.listRecords(metadataPrefix='oai_dc'):
+        print(record)
+
+The pyoai package also contains a generic server implementation of the
+OAI-PMH protocol. It is used as the foundation of the
+`MOAI Server Platform <http://pypi.python.org/pypi/MOAI>`_.
+
+Development
+===========
+
+.. code-block:: bash
+
+    uv sync --all-extras
+    uv run pytest