shrimple go sse example

path	what dat do
/cmd/web	entrypoint
/internal/handler	web handler, passing around reference to sse, could add database connection here
/internal/routes	web routes
/internal/sse	handles connections, heartbeats and broadcasting messages
/internal/jwt	encoding and decoding of jwt tokens, useful for this example as we dont have a database
/templates	contains the js to start an EventSource

todo:

• save messages to repopulate chat history on refresh