doc: replace URL action example with form The example to provide a link to take or resolve an item was broken. Roundup has required a POST not GET for changes to the database for a while. This example was never fixed. Replaced a link using GET with a POSTed form. This changes the activating element from a link to a button. The button could be restyled as a link using CSS I think. The original example was also not canonical. It used :action rather than the canonical @action.

[roundup_test_db]
host=127.0.0.1
port=5432
user=rounduptest
password=rounduptest
dbname=rounduptest

[roundup_test_schema]
host=127.0.0.1
port=5432
user=rounduptest_schema
password=rounduptest
dbname=rounduptest_schema
options=-c search_path=roundup_service_dev

[roundup_test_schema_bad]
host=127.0.0.1
port=5432
user=rounduptest_schema
password=rounduptest
dbname=rounduptest_schema
options=-c search_path=