In-game almanac / elaborate overview of units and buildings

For full details on units, buildings and heroes you now have to consult webpages like http://clashofclans.wikia.com/wiki/Town_Hall
I am missing this information in the game itself. When training or upgrading, some limited information is given, but by far not all, while the information is important for e.g. strategic planning. It would be greatly beneficial to have an in-game detailed overview of all this information.

If not agreed on by Supercell, please consider the following options (let's call it almanac for convenience sake)

• almanac is freely available to everyone; or,
• need to gem almanac to make it available; or,
• information on units/buildings is available only when having them (for the level you have them), the rest can e.g. be gemmed; or,
• let it be part of a reward for a specific achievement.

Or just any method (economically beneficial for SC or not), just as long as all the information can be made available in-game.