Update to docs page code-recipes.md

[franzqat]

I don't understand the issue here #336 but I fixed some examples in code-recipes.md so they can be run correctly without errrors.

There were some calls to owm class instead of weather_manager. Also IDs of cities have been changed to existing ones so the examples can be run correctly

[csparpa]

Sweet, thanks!

[csparpa]

@franzqat as you've issued your PR against the master branch, I've replicated the changes on the develop branch instead Here is the commit: https://github.com/csparpa/pyowm/commit/daaf4100f2052fc0fb950ad844ee62fec360ffce

Releasing those soon

thanks