Document tracking issue policy for continuing goals

[nikomatsakis]

We should add some documentation on resuming previous goals and in particular how to manage the tracking issue. We also should link any 2025h1 goals to 2024h2 as appropriate.

I think we can add a line to the TEMPLATE metadata like | tracking issue | none (if this is a continuing goal, put the existing tracking issue here, otherwise leave it: one will be created for you later).

[lqd]

Goals that are continuations of the last period:

• https://rust-lang.github.io/rust-project-goals/2025h1/annotate-snippets.html
• https://rust-lang.github.io/rust-project-goals/2025h1/async.html
• https://rust-lang.github.io/rust-project-goals/2025h1/cargo-semver-checks.html
• https://rust-lang.github.io/rust-project-goals/2025h1/const-trait.html
• https://rust-lang.github.io/rust-project-goals/2025h1/ergonomic-rc.html
• https://rust-lang.github.io/rust-project-goals/2025h1/formality.html
• https://rust-lang.github.io/rust-project-goals/2025h1/GPU-Offload.html
• https://rust-lang.github.io/rust-project-goals/2025h1/min_generic_const_arguments.html
• https://rust-lang.github.io/rust-project-goals/2025h1/next-solver.html
• https://rust-lang.github.io/rust-project-goals/2025h1/optimize-clippy-linting-2.html
• https://rust-lang.github.io/rust-project-goals/2025h1/parallel-front-end.html
• https://rust-lang.github.io/rust-project-goals/2025h1/Polonius.html
• https://rust-lang.github.io/rust-project-goals/2025h1/pubgrub-in-cargo.html
• https://rust-lang.github.io/rust-project-goals/2025h1/rfl.html
• we likely don't need to track this one separately, as I assume there could be one such goal per period, but here it is: https://rust-lang.github.io/rust-project-goals/2025h1/stabilize-project-goal-program.html
• https://rust-lang.github.io/rust-project-goals/2025h1/std-contracts.html

Some goals have changed scope/names between the 2 periods (e.g. a-mir-formality's goal), and for these it seems preferable to have a new tracking issue and not consider them as continuation.

(For goals that weren't continued, we could also mark their tracking issues with their period in the issue name, and not just via GH milestone, and/or also close them as completed, not planned, etc.)

---

Proposal:

• we link the continuing goals to the previous period's tracking issue
• we post a comment in each tracking issue of the continuing goals as a marker comment, prior to posting the new period's first update
• and mention in the OP the periods to which this goal applies, and link to each marker period.
• in addition to having all of the periods' associated github milestones, if we can have multiple milestones on github which I'm not sure; otherwise, just the most recent one is also fine: changing the milestone will also leave an update event in the github history / comments list, IIRC.

[nikomatsakis]

@lqd can we close this issue? seems like yes.

[lqd]

I believe so: between this, the zulip discussions, and the work done in automation, it feels handled.