[Documentation][IDE] Add a reference to the docs for the intellij-move IDE

There's a project called [intellij-move](https://github.com/pontem-network/intellij-move) which is Move Language Plugin for Jetbrains IDEs. It supports all of them, including the free PyCharm Community. IDE should suggest installing it when any `.move` file is opened, or just download it from the Marketplace in `Settings -> Plugins` section.
We started it in the middle of 2020, and now it's in quite good shape.

Supported features are:
* Parsing of both Move language and MSL
* Name resolution in Move and MSL
* Types and type inference in Move
* Autoformatter
* Support for `Move.toml`, move-cli commands, local deps, git deps (partially)

It would be great to have some official recognition of the project, maybe add a link in the docs.

I know Diem started their own language server at https://github.com/diem/move/tree/main/language/move-analyzer, based on rust-analyzer libraries, but it has only some initial implementation. At Pontem, we tried this approach too (code at [move-language-server](https://github.com/pontem-network/move-language-server)) but it was scrapped when we realized that Diem has started move-analyzer. It has a little bit of parser implemented, I can try to finish the parser later and merge it upstream if needed.