[Feature Request] Automatic documentation comment generation (for methods, types, mods, etc.)

Coming from the worlds of both .NET/Visual Studio and Python, one of the creature comforts I got to expect from an IDE is the automatic generation of documentation comments (or at least the boilerplate for one) for certain types of data (functions/classes, etc).

Most of the crates I have encountered so far have superb documentation. However, the documentation are usually written by hand, and I imagine having an automated tool for generating at least the boilerplate could streamline the process.

Here's an example from a VSCode extension which accomplishes similar goals for python:

In my research, I encountered RFC1574. Furthermore, adopting this suggestion on how implement documentation in a machine-readable way could open up the way for automatic generation of said boilerplate and allow for more fixes in the future, such as:

• Checking for compliance with the structure above.
• Suggesting the user to change the documentation after changes in the code (e.g. adding/removing/reordering function arguments, etc.)

Start by reading RFC1574 and the linked machine-readable inline documentation proposal, then compare their goals with rust-analyzer's current capabilities. The issue does not name files, tests, or an entry point; work is complete only after the scope and implementation approach for generating documentation-comment boilerplate are defined and accepted.