Liquipedia is good, but is better that all the unit information (cost, build-time, cargo, upgrades, vision, etc.) appear IN the game, both IN-game and help window. Is better the official Blizzard information than any other.
Starcraft fandom also got this kind of data, and it can be filled with data from the map editor (in this case latest and more correct data from Data (and Triggers for special maps) sections).
Official ingame help and menu information offers a simpler version, the basics for beginners. Liquipedia is the reference encyclopedia for those who want to go further. As for Fandom that Undead version, it’s particularly helpful regarding the lore, as Liquipedia is almost devoid of this aspect. 
PS : when you say something, just « is better » is fine ; but when you ask a question you should add a pronoun « Is it better ? ». Otherwise, readers may have a tough time understanding you.
I know, I didn’t mistake.
I guess Blizzard has done the right thing in putting in-game just basic information, otherwise a kind of information-overload would occur.
For more in-depth as Trias said the Liquipedia is the way to go.
Just a curiosity: Archon generally is known as possessing splash. Can anybody point to any source where precise stats are listed? (radius of AOE and the way this splash works)?
I want to know exactly the amount of splash damage of archons, tanks, liberators, bound of mutas. All that info IN the game will improve the gameplay.
Technically Mutas have a curious kind of splash. Their primary, secondary and tertiary attack are unlike Protoss-spell-splash (Storm Nova) affected by Armor.
A Sentry with GS works wonders in minimising the Muta’s damage.