better explain what code disctionary contains

https://github.com/codespell-project/codespell/pull/2144#issuecomment-966919948

codespell_lib/_codespell.py

diff --git a/codespell_lib/_codespell.py b/codespell_lib/_codespell.py
index becf4d4..d02407c 100644
--- a/codespell_lib/_codespell.py
+++ b/codespell_lib/_codespell.py
@@ -58,7 +58,7 @@
         True, True, supported_languages_en, supported_languages_en),
     ('usage', 'for replacing phrasing with recommended terms', '_usage',
         None, None, None, None),
-    ('code', 'for words common to code and/or mathematics that might be typos', '_code',  # noqa: E501
+    ('code', 'for words from code and/or mathematics that are likely typos in other context (such as uint)', '_code',  # noqa: E501
         None, None, None, None,),
     ('names', 'for valid proper names that might be typos', '_names',
         None, None, None, None,),