docs(ci): replace YAML copy with link to .forgejo/workflows/ci.yml

Per mara's feedback: don't copy the YAML inline, just reference the file.

docs/ci.md

@@ -110,42 +110,7 @@ to avoid provisioning collisions.
 
 ## CI workflow
 
-Three jobs are defined in `.forgejo/workflows/ci.yml`:
-
-```yaml
-name: CI
-on:
-  pull_request:
-    branches: ["**"]
-  # workflow_dispatch lets `hive-forge ci-rerun --pr N` retrigger without
-  # an empty commit.
-  workflow_dispatch:
-
-jobs:
-  check:
-    name: nix flake check
-    runs-on: [hive-ci]
-    timeout-minutes: 30
-    steps:
-      - uses: actions/checkout@v3
-      - run: nix flake check
-
-  tracker-tags:
-    name: tracker-tag lint
-    runs-on: [hive-ci]
-    timeout-minutes: 5
-    steps:
-      - uses: actions/checkout@v3
-      - run: sh scripts/check-issue-refs.sh
-
-  comment-blocks:
-    name: comment-block lint
-    runs-on: [hive-ci]
-    timeout-minutes: 5
-    steps:
-      - uses: actions/checkout@v3
-      - run: sh scripts/check-comment-blocks.sh
-```
+Three jobs are defined in [`.forgejo/workflows/ci.yml`](../.forgejo/workflows/ci.yml):
 
 - **`nix flake check`** — all flake checks: formatting (treefmt+rustfmt),
   cargo test, cargo clippy, module evaluation, `hivectl-docs` freshness.