Update the database *after* printing about tldr-python-client

[metov]

I think an alternative, less invasive solution would be for me to simply create a systemd timer that runs tldr --update_cache every day or so, which would ensure that the cache is never stale.

If this is the recommended solution, though, it would be useful to have a new --update-all argument, which pulls all of the pages rather than what's in the cache. The entire tldr pages repo is currently only 27 MB, so the latency-space tradeoff seems reasonable.