Cofounder here, thanks for your feedback! This is indeed an early version, and to answer your points more precisely:

- This is indeed planned, and as you can see in the comments you're not the only one thinking that! It cannot be done with a bookmarklet but we will release Chrome and Firefox extensions that will have this feature.

- I don't get what you mean by "something sidebar-like", are you talking of a pannel on the top of your screen automatically displaying the summary if it exists?

- Yep, building an active community around tldr.io will likely be key to its success. We are thinking hard on how to do it, and if you have any ideas or suggestion they are more than welcome