For example, I made a drawing about Charmeleon (in 1920×1080 resolution), is it allowed to attach somewhere on the website? :)
Not really. Sharing creations and artwork isn’t really the point of this site — PokeBase follows a strict question and answer format for the most part. That type of content doesn’t fit the platform well.
You’re not totally without options though. If you can catch some activity on the chat room you might find some folks who’d be interested in fan art, but otherwise this site probably isn’t the place for sharing artwork.
If you’d like to share original works on a platform similar to this one, r/pokemon tends to be pretty receptive to art and fan-made content, though obviously they don’t have any affiliation with us.