[Docs] Update review app docs to include info on deletion

docs/creating_review_app.md

@@ -36,6 +36,19 @@ CircleCI will match the `review-app-` prefix and either:
 1. Create a review app using `build_review_app.sh` if the review app doesn't
    exist yet (i.e. first successful push of the branch), or
 2. Update an existing review app using `update_review_app.sh`
+3. Once CI is complete follow [this step](https://github.com/artsy/force/blob/master/docs/creating_review_app.md#dns-setup) to setup DNS.
+
+> Once you're done working with the review app it (currently) has to be deleted manually
+
+#### Deleting a Review App
+
+Run:
+
+```sh
+yarn delete-review-app <name>
+```
+
+The `name` is the name of the branch, minus the `review-app-` prefix.
 
 #### Manual Steps
 

package.json

@@ -20,6 +20,7 @@
     "compile": "babel src/v2 --out-dir dist/v2 -s --source-map --extensions '.js,.jsx,.ts,.tsx' --ignore src/v2/**/__tests__,src/v2/**/__stories__",
     "cypress:run": "./node_modules/.bin/cypress run",
     "cypress": "./node_modules/.bin/cypress open",
+    "delete-review-app": "kubectl --context staging delete namespace",
     "jest": "JEST_JUNIT_OUTPUT=reports/junit/js-test-results.xml node --expose-gc --max_old_space_size=4096 ./node_modules/.bin/jest --no-cache --runInBand --logHeapUsage",
     "lint": "eslint --cache --cache-location '.cache/eslint/' --ext ts,tsx --ignore-pattern 'src/v2/__generated__'",
     "mocha": "scripts/mocha.sh",