more docs

Author: Zulko

python_codon_tables/README.rst

@@ -74,3 +74,17 @@ Usage
     table = pct.download_codons_table(taxid=316407)
     print (table['*']['UGA'])  # returns 0.29
 
+If you have an internet connection you can also enter any taxid in
+``get_codons_table`` and the table will be downloaded from the Kasuza website.
+You can write for instance:
+
+.. code:: python
+
+    table = get_codons_table(1423)
+    table = get_codons_table("1423")
+    table = get_codons_table("b_subtilis_1423")
+    table = get_codons_table("b_subtilis")
+
+In the last line above we provided a "shorthand" notation ``b_subtilis``, which
+will be automatically extended to b_subtilis_1423 as it appears so in the
+built-in table (use this feature at your own risks!)