Readme example doesn't work
The first example in the readme:
```nim
import htmlgen
import jester

routes:
  get "/":
    resp h1("Hello world")
```
when compiled with Nim 0.19.9 gives:

```
../../.nimble/pkgs/jester-0.4.1/jester.nim(473, 8) Error: type mismatch: got <proc (req: Request): Future[system.void]{.cl
osure, locks: <unknown>.}, Settings>
but expected one of:
proc run(onRequest: OnRequest; settings: Settings)
  first type mismatch at position: 1
  required type: OnRequest
  but expression 'proc (req: httpbeast.Request): Future[void] = result = handleRequest(jes, req)' is of type: proc (req: R
equest): Future[system.void]{.closure, locks: <unknown>.}
  This expression is not GC-safe. Annotate the proc with {.gcsafe.} to get extended error information.
proc run(onRequest: OnRequest)
  first type mismatch at position: 1
  required type: OnRequest
  but expression 'proc (req: httpbeast.Request): Future[void] = result = handleRequest(jes, req)' is of type: proc (req: R
equest): Future[system.void]{.closure, locks: <unknown>.}
  This expression is not GC-safe. Annotate the proc with {.gcsafe.} to get extended error information.

expression: run(proc (req: httpbeast.Request): Future[void] = result = handleRequest(jes, req),
    initSettings(self.settings.port, self.settings.bindAddr))
```

----

Other than that, it is not the same example that could be found in `tests/example.nim`.