Documentation links to the old hkcancor site, but it has been moved to github.

[fcbond]

Describe the bug

The tagset documentation links to a site which no long exists.
http://compling.hss.ntu.edu.sg/hkcancor/

It should link to:

https://github.com/fcbond/hkcancor

To reproduce
Click on the link http://compling.hss.ntu.edu.sg/hkcancor/

Expected behavior
It should go to the new URL

Screenshots
If applicable, add screenshots to help explain your problem.

System (please complete the following information):

• Operating System: [e.g. Windows, MacOS, Linux]
• PyCantonese version: [What you see after you run import pycantonese; print(pycantonese.__version__)]

Additional context
Add any other context about the problem here.

grep -R compling *
CHANGELOG.md:* [The Hong Kong Cantonese Corpus](http://compling.hss.ntu.edu.sg/hkcancor/) is included in the package.
docs/tutorials/lee-pycantonese-2021-05-16.ipynb:    "PyCantonese is shipped with the [Hong Kong Cantonese Corpus](http://compling.hss.ntu.edu.sg/hkcancor/) (HKCanCor, CC BY license). We are going to use this corpus a lot in this tutorial."
docs/tutorials/lee-pycantonese-2021-05-16.ipynb:    "* `pos`: part-of-speech tag (see the [HKCanCor documentation](http://compling.hss.ntu.edu.sg/hkcancor/) for the POS tagset)\n",
docs/tutorials/lee-pycantonese-2021-05-16.ipynb:    "1. What is the part-of-speech tag for classifiers. Check the [HKCanCor documentation](http://compling.hss.ntu.edu.sg/hkcancor/).\n",
docs/searches.html:<p>For the part-of-speech tagset used by HKCanCor, see <a class="reference external" href="http://compling.hss.ntu.edu.sg/hkcancor/">here</a>.</p>
docs/changelog.html:<li><p><a class="reference external" href="http://compling.hss.ntu.edu.sg/hkcancor/">The Hong Kong Cantonese Corpus</a> is included in the package.</p></li>
docs/generated/pycantonese.pos_tagging.hkcancor_to_ud.html:are described at <a class="reference external" href="http://compling.hss.ntu.edu.sg/hkcancor/">http://compling.hss.ntu.edu.sg/hkcancor/</a>).
docs/generated/pycantonese.pos_tag.html:<a class="reference external" href="http://compling.hss.ntu.edu.sg/hkcancor/">http://compling.hss.ntu.edu.sg/hkcancor/</a>.</p></li>
docs/source/changelog.rst:* `The Hong Kong Cantonese Corpus <http://compling.hss.ntu.edu.sg/hkcancor/>`_ is included in the package.
docs/source/pos_tagging.rst:(`46 of which are described <http://compling.hss.ntu.edu.sg/hkcancor/>`_).
docs/source/searches.rst:For the part-of-speech tagset used by HKCanCor, see `here <http://compling.hss.ntu.edu.sg/hkcancor/>`_.
docs/source/data.rst:`Hong Kong Cantonese Corpus <http://compling.hss.ntu.edu.sg/hkcancor/>`_
docs/_modules/pycantonese/pos_tagging/hkcancor_to_ud.html:<span class="c1"># HKCanCor tagset: http://compling.hss.ntu.edu.sg/hkcancor/</span>
docs/_modules/pycantonese/pos_tagging/hkcancor_to_ud.html:<span class="sd">    are described at http://compling.hss.ntu.edu.sg/hkcancor/).</span>
docs/_modules/pycantonese/pos_tagging/tagger.html:<span class="sd">          http://compling.hss.ntu.edu.sg/hkcancor/.</span>
docs/_sources/data.rst.txt:`Hong Kong Cantonese Corpus <http://compling.hss.ntu.edu.sg/hkcancor/>`_
docs/_sources/changelog.rst.txt:* `The Hong Kong Cantonese Corpus <http://compling.hss.ntu.edu.sg/hkcancor/>`_ is included in the package.
docs/_sources/pos_tagging.rst.txt:(`46 of which are described <http://compling.hss.ntu.edu.sg/hkcancor/>`_).
docs/_sources/searches.rst.txt:For the part-of-speech tagset used by HKCanCor, see `here <http://compling.hss.ntu.edu.sg/hkcancor/>`_.
docs/pos_tagging.html:(<a class="reference external" href="http://compling.hss.ntu.edu.sg/hkcancor/">46 of which are described</a>).
docs/data.html:<a class="reference external" href="http://compling.hss.ntu.edu.sg/hkcancor/">Hong Kong Cantonese Corpus</a>
src/pycantonese/pos_tagging/tagger.py:          http://compling.hss.ntu.edu.sg/hkcancor/.
src/pycantonese/pos_tagging/hkcancor_to_ud.py:# HKCanCor tagset: http://compling.hss.ntu.edu.sg/hkcancor/
src/pycantonese/pos_tagging/hkcancor_to_ud.py:    are described at http://compling.hss.ntu.edu.sg/hkcancor/).
src/pycantonese/data/hkcancor/README.md:http://compling.hss.ntu.edu.sg/hkcancor/
src/pycantonese/data/hkcancor/README.md:([here](http://compling.hss.ntu.edu.sg/hkcancor/data/LICENSE),
tests/test_docs.py:        # "http://compling.hss.ntu.edu.sg/hkcancor/",  # TODO: Is the site down?