Changes for default settings between Trello and Bitbucket Cloud integrations

[#1]

When Trello became part of Atlassian it was obvious we wanted to integrate Trello and Bitbucket Cloud. Linking cards in Trello to open pull requests, branches, and commits while providing quick access to your team's Kanban board within Bitbucket Cloud just makes sense for development teams.

To enable this integration we created a Bitbucket Cloud Power-up for Trello that allows users to link specific pull requests, branches, and commits from Bitbucket Cloud. With this connection you can easily track the status of your product development.

From the other side we also created a Connect app in Bitbucket Cloud that provides a "Boards" view in your repository to link any Trello boards that are important to your team.

In order to automate this integration and make it as seamless as possible we made the Power-Up and the Connect App work in concert. When you create a link from Trello to a repository in Bitbucket Cloud the Power-Up was designed to automatically create a link in Bitbucket Cloud and add this board to your "Boards" view of that repository. Likewise, when you add a Trello board in Bitbucket Cloud the Connect App was originally designed to invite other contributors on your repository to join your Trello Board. 

This works great for small teams with a flat organization structure but for larger teams with different privacy needs we decided that automatically connecting boards to repositories and inviting users provided too much automation. In order to give Trello board owners and Bitbucket Cloud owners more visible control over how the two products are integrated we have decided to disconnect the automatic connection between the Trello Power-Up and the Bitbucket Cloud Connect App. No functionality will be lost.

Repository admins in Bitbucket Cloud will still be able to link to any Trello Board of which they are a member. They can also choose to auto-invite any user to join their board. The default setting for invitations is now set to "Nobody" whereas before it was set to "Write" (any contributor). This new default will apply to all Trello boards added to Bitbucket repositories going forward.

In addition, because people adding Trello boards to their repositories might not have realized that other users were automatically invited to the board, we are resetting the invitation status of all integrations in Bitbucket Cloud to "Nobody" as well to prevent any new repository users from being automatically invited to these boards. You can still change the settings in your repository to auto-invite any users to your board but we wanted to make this setting an explicit change by the admin.

With the Trello Power-Up you can connect a card to any commit, branch, or pull request on any Bitbucket Cloud repository that you have "Read" access on. That has not changed. However, going forward adding a link from Trello will not automatically create a link in your repository. If you want to add your Trello board to the "Boards" view of your repository you will need to add it explicitly from Bitbucket Cloud.

We hope that these changes clarify how the two products can be integrated together to enable your teams success. Thank you for using Bitbucket Cloud and Trello.