cache lint to reduce load (#343)

Signed-off-by: Jordan <jordan@nimblewidget.com>

Author: grokspawn

.github/workflows/lint.yaml

@@ -7,6 +7,11 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
+      - name: htmlproofer cache
+        uses: actions/cache@v4
+        with:
+          path: public/linter-cache.json
+          key: {{ runner.os }}-htmlproofer
       - uses: actions/setup-go@v4
         with:
           go-version-file: go.mod

hack/ci/link-check.sh

@@ -8,4 +8,4 @@ CONTAINER_ENGINE=${CONTAINER_ENGINE:="docker"}
 # 1: links going back to help.github.com are rate-limited and can make this flaky
 # 2: docsy autogenerated edit links to original markdown source, which will fail if the markdown file is new
 # 3: ignore localhost link to a hugo site
-${CONTAINER_ENGINE} run --rm -v $(pwd)/public:/target mtlynch/htmlproofer /target --ignore-empty-alt --ignore-status-codes 429 --allow-hash-href --no-check-external-hash --ignore-urls '/help.github.com/,/edit\/master\/.*\.md/,/tree\/master\/.*\.md/,/new\/master\/.*filename=change-me\.md/,/localhost:1313/'
+${CONTAINER_ENGINE} run --rm -v $(pwd)/public:/target mtlynch/htmlproofer /target --ignore-empty-alt --ignore-status-codes 429 --allow-hash-href --no-check-external-hash --ignore-urls '/help.github.com/,/edit\/master\/.*\.md/,/tree\/master\/.*\.md/,/new\/master\/.*filename=change-me\.md/,/localhost:1313/' --cache  '{ "timeframe": { "external": "30d", "internal": "2w" }, "cache_file": "linter-cache.json", "storage_dir": "/target" }'