Mohammad,
I support this initiative and will contribute. I would however voice a concern and a solution. As a super user rather than developer I am bound to the wiki way, I cant easily resort to the developer insight. I look closely at every feature and every release. Especially where I have a need I test out the new feature.
Concern: Many of the new features including some older ones come with very minimal documentation, they are not well understood or documented to begin with and this stays true for a long period. You can also see how possible solutions to live questions are rarely demonstrated using some of these features when one would think they could be. They may make sense to those involved in the development but often not to other users.
I personally have attempted to use such features myself and quite commonly find the release information and the PR of little or no use. Basically it can sometimes be too hard to learn how to use such a feature successfully or at all.
Solution: I think we should give the developers and people with a deeper understanding a place and encouragement, to provide some examples and informal descriptions and suggestions how to use these features, there is no need to demand full and appropriate documentation from developers, only that they brief us and show the way. Obsessives such as myself (perhaps you) will then explore them more fully, be able to solve problem’s with them and have the capacity to produce documentation in somewhat plain English and thus democratise them more. Once the ball starts rolling on a feature it starts to have a presence, ends up here in the community and good examples can fuel the documentation.
Some current release examples include the message catcher and event catcher widgets.
Honestly this is why I think too many features do not get out of the engineering lab, and thus the documentation is not able to grow. How can I document something well, if I do not know how to use it myself?. This also occurs with techniques used in the core. Many of these could be referenced and reused if the documentation was friendlier. An example is the newish layout feature, the UI is so deeply dependant on tiddlywiki bespoke CSS classes, it can be hard to get anywhere.
There are plenty of counter examples and helpful deeply aware people but it seems only chance if they get to provide that little extra insight needed.