Docs: npm plans relating to native binaries and postinstall scripts

[lovell]

Hello, the "Limitations" > "Native binaries and NPM postinstall scripts" section of this repo's README contains the statement that there are "no plans on remediating the behavior".

https://github.com/stackblitz/webcontainer-core/blob/main/README.md#limitations

If you weren't already aware, yarn has a public RFC relating to this - see yarnpkg/berry#2751

In response, the npm team are now also planning an RFC - see yarnpkg/berry#2751 (comment)

Although these proposals won't solve the problem on their own, they are a very welcome step towards doing so, and may qualify as "plans on remediating the behavior". 🤞