Add P-critical to issues of note and make it more render friendly

templates/agenda.tt

@@ -78,10 +78,10 @@ tags: prioritization, rustc
   - [M of those are unassigned](https://github.com/rust-lang/rust/issues?utf8=%E2%9C%93&q=is%3Aopen+is%3Aissue+label%3AT-compiler+label%3AP-critical+no%3Aassignee)
 - [N P-high issues](https://github.com/rust-lang/rust/issues?utf8=%E2%9C%93&q=is%3Aopen+is%3Aissue+label%3AT-compiler+label%3AP-high+)
   - [M of those are unassigned](https://github.com/rust-lang/rust/issues?utf8=%E2%9C%93&q=is%3Aopen+is%3Aissue+label%3AT-compiler+label%3AP-high+no%3Aassignee)
-- [N P-high, M P-medium, P P-low regression-from-stable-to-beta](https://github.com/rust-lang/rust/labels/regression-from-stable-to-beta)
-  - The only assigned are the P-high ones.
-- [N P-high, M P-medium, P P-low regression-from-stable-to-nightly](https://github.com/rust-lang/rust/labels/regression-from-stable-to-nightly)
-  - There are N P-medium assigned.
+- [X P-critical, N P-high, M P-medium, P P-low regression-from-stable-to-beta](https://github.com/rust-lang/rust/labels/regression-from-stable-to-beta)
+  - X P-critical, N P-high, M P-medium, P P-low assigned
+- [X P-critical, N P-high, M P-medium, P P-low regression-from-stable-to-nightly](https://github.com/rust-lang/rust/labels/regression-from-stable-to-nightly)
+  - X P-critical, N P-high, M P-medium, P P-low assigned
 - [N regression-from-stable-to-stable](https://github.com/rust-lang/rust/labels/regression-from-stable-to-stable)
   - [M of those are not prioritized](https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3Aregression-from-stable-to-stable+-label%3AP-critical+-label%3AP-high+-label%3AP-medium+-label%3AP-low).