fix(ci): correct image for generating slate docs

.woodpecker/docs.yml

@@ -23,14 +23,18 @@ pipeline:
   slate-docs:
     image: 'slatedocs/slate'
     group: 'generate'
+    # Slate requires a specific directory to run in
     commands:
-      - cd docs/api
-      - bundle exec middleman build --clean
+      - rm -rf /srv/slate/source
+      - mv "$CI_WORKSPACE/docs/api" /srv/slate/source
+      - cd /srv/slate
+      - /srv/slate/slate.sh build
+      - mv /srv/slate/build "$CI_WORKSPACE/docs/api-build"
 
   archive:
     image: 'alpine'
     commands:
-      - cp -r docs/api/build docs/public/api
+      - cp -r docs/api-build docs/public/api
       - 'cd docs/public && tar czvf ../../docs.tar.gz *'
       - 'cd ../../src/_docs && tar czvf ../../api-docs.tar.gz *'
     when: