update "entered" agenda should be pre-selected

[mirjak]

Description

When you update an agenda that was entered using the "Enter agenda" function, it would be nice if the "Enter agenda" button would be selected and the text shown by default for any further updates. I did this last time and my co-chair didn't notice which made things unnecessarily complex.

Code of Conduct

• I agree to follow the IETF's Code of Conduct

[richsalz]

It seems that the thing to do is if there IS an agenda already, change the default radio button to by 'modify' which will bring the text on screen for editing. That seems a little hard to do, at first glance, but I am a django noob.