The documentation for Canister<'agent, ManagementCanister> is too hard to find

[luc-mercier]

The documentation at https://agent-rust.netlify.app/ic_utils/interfaces/management_canister/struct.managementcanister show only 2 functions: create and set_agent.

But the "interesting" functions of the management canister are not directly inside ManagementCanister. Instead, there are in Canister<'agent, ManagementCanister>. For instance, this is where create_canister and install_code is.

I cannot find the documentation for those without looking at the code. Purely using the doc, I really could not understand how I can use the ManagementCanister interface.

We should make sure that the doc of ManagementCanister links to wherever the "real" doc of the interface is.