add docs cache

docs/cache.md

@@ -0,0 +1,39 @@
+## Cached
+
+When you run the server, OpenAPI process your specification and this process can be take several minutes for long ontologies. In addition, every restart is going to trigger the process.
+
+Due to the previous errors, the Python server generated by OBA creates a cache file of the specification avoiding to generates if the specification didn't changed.
+
+
+### Docker
+
+If you are using Docker, please use volumes
+
+```bash
+$  docker run -v $PWD/openapi_server/openapi/:/usr/src/app/openapi_server/openapi/ <docker_image>
+```
+
+```bash
+$  docker run -v $PWD/openapi_server/openapi/:/usr/src/app/openapi_server/openapi/ dbpedia_music
+2020-05-23 00:23:54,109 - openapi_server.cached - WARNING - Cache file does not exist: [Errno 2] No such file or directory: '/usr/src/app/openapi_server/openapi/openapi.yaml.cache'
+ * Serving Flask app "__main__" (lazy loading)
+ * Environment: production
+   WARNING: This is a development server. Do not use it in a production deployment.
+   Use a production WSGI server instead.
+ * Debug mode: off
+2020-05-23 00:23:54,422 - werkzeug - INFO -  * Running on http://0.0.0.0:8080/ (Press CTRL+C to quit)
+
+ ```
+
+ ```bash
+ 
+$  docker run -v $PWD/openapi_server/openapi/:/usr/src/app/openapi_server/openapi/ dbpedia_music
+ * Serving Flask app "__main__" (lazy loading)
+ * Environment: production
+   WARNING: This is a development server. Do not use it in a production deployment.
+   Use a production WSGI server instead.
+ * Debug mode: off
+2020-05-23 00:24:17,308 - werkzeug - INFO -  * Running on http://0.0.0.0:8080/ (Press CTRL+C to quit)
+^C%
+
+```