[Pattern Draft] The Outreach Sandwich - Keeping contributions moving

In a conversation @MaineC mentioned that @rrrutledge “has a way to follow up at just the right time, to remind me that I need to do something on my PR (contribution)”. Well, it turns out that this happens at the right time because there is a strict regimen behind this that Russ follows :)

I interviewed Russ about this, and captured some notes. [^1]
Now we are looking to turn these notes into a pattern. The first draft of that is already in the doc above.

WIP Patlet:

The communication on some external contributions threads to an InnerSource project are going stale, even though the contributor was motivated when starting the process. By using the outreach sandwich, a structured way to do the follow-up on all open contribution threads, the project maintainers manage to nurture more contributions to completion.

A little sketch that may help to understand the idea behind this pattern.
Don't mind the styling, GitHub does not allow all styling options for mermaid diagrams:

flowchart TD
    subgraph checks [" "]
        X(Start checks on regular cadence) --> A
        A(Take next item from board) --> B
        B("`**Progress Check**: Any updates on the contribution?`") -->|yes| A
        B --> |no| C
        C("`**Time Check**: Enough time since last outreach?`") --> |no| A
        C --> |yes| D
        D("`**History Check**: How many previous outreaches?`") --> |"0/1/2"| send_outreach
        D --> |"3"| stop_outreach
    end

    subgraph send_outreach [Send Outreach]
        OR1("`**Template**: Pick appropriate outreach approach`") --> OR2
        OR2("`**Communication Method**: How to effectively reach the contributor?`") --> OR3
        OR3("`**Send Outreach**`")
    end
    send_outreach --> A

    subgraph stop_outreach ["Stop Outreach"]
        ST1(Inform Contributor) --> ST2
        ST2(Close issue/item)
    end
    stop_outreach --> A

    style send_outreach fill:#edf6fb,stroke:#0aa8a7,stroke-width:2px
    style stop_outreach fill:#edf6fb,stroke:#0aa8a7,stroke-width:2px

[^1]: If anybody reading this cannot access the doc, please let me know in the comments.

Start with the linked Google Doc and the WIP Patlet in this issue; compare the interview notes and existing draft with the Outreach Sandwich flow. Done means a reviewed, self-contained pattern draft with the process, outreach limits, and diagram clarified, including a resolution for readers who cannot access the document.