Add initial type defintions

[bobcatfish]

Expected behavior

We should have the structure of the types we want to add for Tekton Triggers clearly defined in this repo and agreed on by all owners:

• EventListener
• TriggerBinding
• TriggerTemplate

Each type should:

• Be defined in go such that it can be fed to update-codegen.sh
• Be agreed on by all owners
• Be clearly documented in comments (so that it would be fully documented in godoc form)
• Have an example in an examples dir (even if we aren't testing this yet, see Add automated coverage for examples #11)

Actual behavior

The structure of the types is basically just in exist in example yaml in the design doc which means that:

1. the actual structure and purpose of each field is not clearly defined
2. each person reviewing + authoring may have a different idea of what the field actually is

Additional info

Design for these types lives in https://docs.google.com/document/d/1fngeNn3kGD4P_FTZjAnfERcEajS7zQhSEUaN7BYIlTw/edit (visible to members of tekton-dev)

[iancoffey]

Closed prematurely, theres still items to address despite the PR being merged 😅

[ncskier]

@iancoffey What work is still left under this issue? Is it the work outlined in this comment?

[iancoffey]

@ncskier Yes, I just wanted to make sure I made followup issues if they didnt exist for each of those items (which I have not done yet). Totally cool with closing if thats not needed, or I will check that out tomorrow.

[ncskier]

Ok, sounds good! I was just looking over the issues for another one to pick up, and I wasn't positive what was left to do for this one 😁That would be great if you could create new issues documenting the remaining work 👍

[iancoffey]

This is long since merged, Im going to close this one.