refactor: Simplify handler signatures and add server runner

- Pass URL params as direct arguments to handlers
- Use `ctx.get_custom_header` to retrieve session key
- Add a runnable script to start the heroserver
- Clean up formatting in documentation and code
- Remove unused redisclient import

examples/hero/heroserver/heroserver.vsh

@@ -0,0 +1,6 @@
+#!/usr/bin/env -S v -n -w -cg -gc none -cc tcc -d use_openssl -enable-globals run
+
+import freeflowuniverse.herolib.hero.heroserver
+
+mut server := heroserver.new_server(port: 8080)!
+server.start()!