rustc-dev-guide: Date Annotations, Table of Contents, Issue Triage, and Rfcbot Labels

For the action to pick the date, add a special annotation before specifying the date: ```md  Apr 2025 ``` Example: ```md As of  Apr 2025, the foo did the bar. ``` For cases where the date should not be part of the visible rendered output, use the following instead: ```md  ``` - A link to a relevant WG, tracking issue, `rustc` rustdoc page, or similar, that may provide further explanation for the change process or a way to verify that the information is not outdated. - If a text grows rather long (more than a few page scrolls) or complicated (more than four subsections), it might benefit from having a Table of Contents at the beginning, which you can auto-generate by including the `` marker at the top. ## Issue triage Please see <https://forge.rust-lang.org/release/issue-triaging.html>. [stable-]: https://github.com/rust-lang/rust/labels?q=stable [beta-]: https://github.com/rust-lang/rust/labels?q=beta [I-\*-nominated]: https://github.com/rust-lang/rust/labels?q=nominated [I-prioritize]: https://github.com/rust-lang/rust/labels/I-prioritize [tracking issues]: https://github.com/rust-lang/rust/labels/C-tracking-issue [beta-backport]: https://forge.rust-lang.org/release/backporting.html#beta-backporting-in-rust-langrust [stable-backport]: https://forge.rust-lang.org/release/backporting.html#stable-backporting-in-rust-langrust [metabug]: https://github.com/rust-lang/rust/labels/metabug [regression-]: https://github.com/rust-lang/rust/labels?q=regression [relnotes]: https://github.com/rust-lang/rust/labels/relnotes [S-tracking-]: https://github.com/rust-lang/rust/labels?q=s-tracking ### Rfcbot labels [rfcbot] uses its own labels for tracking the process of coordinating asynchronous decisions, such as approving or rejecting a change. This is used for [RFCs], issues, and pull requests. | Labels | Color | Description | |--------|-------|-------------| | [proposed-final-comment-period] |   Gray | Currently awaiting signoff of all team members in order to enter the final comment period. | | [disposition-merge] |   Green | Indicates the intent is to merge the change. | | [disposition-close] |   Red | Indicates the intent is to not accept the change and close it. | | [disposition-postpone] |   Gray | Indicates the intent is to not accept the change at this time and postpone it to a later date. |

This section details how to use date annotations in the rustc-dev-guide to indicate the age of information, including using the `` annotation for CI. It also mentions adding a table of contents for long or complicated text using ``. It links to the issue triage guide. Finally, it explains the Rfcbot labels used for tracking asynchronous decisions, with descriptions of labels like `proposed-final-comment-period`, `disposition-merge`, `disposition-close`, and `disposition-postpone`.