add step to verify docs on area/documentation PRs (#1528)

* add step to verify docs on area/documentation PRs

* use GH actions to run the verification

* add check if label is set to area/documentation

* fix broken links in docs with WIP files

* add generating API docs before verifying

Signed-off-by: Sebastian Malton <sebastian@malton.name>

package.json

@@ -40,6 +40,7 @@
     "lint": "yarn run eslint $@ --ext js,ts,tsx --max-warnings=0 src/ integration/ __mocks__/ build/ extensions/",
     "lint:fix": "yarn run lint --fix",
     "mkdocs-serve-local": "docker build -t mkdocs-serve-local:latest mkdocs/ && docker run --rm -it -p 8000:8000 -v ${PWD}:/docs mkdocs-serve-local:latest",
+    "verify-docs": "docker build -t mkdocs-serve-local:latest mkdocs/ && docker run --rm -v ${PWD}:/docs mkdocs-serve-local:latest build --strict",
     "typedocs-extensions-api": "yarn run typedoc --ignoreCompilerErrors --readme docs/extensions/typedoc-readme.md.tpl --name @k8slens/extensions --out docs/extensions/api --mode library --excludePrivate --hideBreadcrumbs --includes src/ src/extensions/extension-api.ts"
   },
   "config": {