List and doc all supported capabilities

[alpe]

Follow up from CosmWasm/wasmd#980 (comment)

It would be nice to have a .md file that contains a list and description of available capabilities. I have a hard time myself to find them

[uint]

Would it be sufficient to add missing "built-in" capabilities to this list?

cosmwasm/docs/CAPABILITIES.md

Lines 89 to 95 in cd9ca86

	- `iterator` is for storage backends that allow range queries. Not all types of
	databases do that. There are trees that don't allow it and Secret Network does
	not support iterators for other technical reasons.
	- `stargate` is for messages and queries that came with the Cosmos SDK upgrade
	"Stargate". It primarily includes protobuf messages and IBC support.
	- `staking` is for chains with the Cosmos SDK staking module. There are Cosmos
	chains that don't use this (e.g. Tgrade).

[webmaster128]

Yes. However, I'd go a small step further and call them "well known capabilities" (or "built-in capabilities", not sure what is best) and extract the list into a new document. This way we have dedicated links that describe the concept and list the capabilities designed by us.

[webmaster128]

I just made a small edit on naming. Not sure what's best. But "Common" is too generic.

[uint]

Yeah, I was thinking of changing it to "all built-in capabilities" too. It seems more accurate.

[webmaster128]

+1 for "built-in capabilities". I like it more than "well known".