Make the crawler work

1) add the crawler binary and fix the crawler library
2) remove the readiness probe in the search backend
3) add config for redis keystore
4) add github_api_secret.txt file with instructions

api/internal/crawl/config/crawler/base/kustomization.yaml

@@ -5,7 +5,9 @@ configmapGenerator:
 - name: crawler-http-cache
   literals:
   - redis-cache-url="redis://redis-http-cache:6379"
-
+- name: redis-keystore
+  literals:
+  - keystore-url="redis://redis-docs-keystore:6379"
 
 secretGenerator:
 - name: github-access-token