add API architecture diagram

Author: MoralCode

Database/api.md

@@ -11,7 +11,9 @@ airtable limits the API to 5 requests per second and suggests using a caching se
 using a GCP f1-micro instance that should theoretically not cost money (or cost very little) we have set up such a caching server at https://api.vacfind.org. 
 
 ### Caching server architecture/setup
-the caching server uses caddyserver.com to provide HTTPS, varnish to provide the caching, and stunnel as an HTTPS client to make requests to Airtable's API because varnish doesnt support HTTPS or seemingly remote backends very easily.
+![VacFind API Data flow diagram](../static/API-Architecture.png)
+
+The caching server uses caddyserver.com to provide HTTPS, varnish to provide the caching, and stunnel as an HTTPS client to make requests to Airtable's API because varnish doesnt support HTTPS or seemingly remote backends very easily.
 
 
 To be totaly honest, I dont think there is anything about our caching server that limits it to being used for just our airtable bases, so theoretically anyone can use their own base ID and APIkeys to read (not sure how the caching will interact with attempts to write. This may require more configuration) from their own airtable bases.