docs: Adding `:stub-columns:` to all csv tables.

Signed-off-by: Tim 'mithro' Ansell <me@mith.ro>
diff --git a/docs/rules/errors.rst b/docs/rules/errors.rst
index 2b17609..75b58a0 100644
--- a/docs/rules/errors.rst
+++ b/docs/rules/errors.rst
@@ -8,4 +8,5 @@
 .. csv-table:: Table - Error Messages
    :file: errors.csv
    :header-rows: 1
+   :stub-columns: 1
    :widths: 10, 10, 80