Allow to use alternative monaco-editor-core packages

[akosyakov]

The last release of Monaco broke Theia, since they removed unused code which is used by Theia. For Theia we are going to publish an alternative package to monaco-editor-core with needed code. Here, we are going to remove runtime dependency and the client will be responsible to provide Monaco.

[nikeee]

If I understand this right, shouldn't this be a peerDependency?

[akosyakov]

@nikeee hi, I've tried it, but they have 2 drawbacks:

• they don't get installed, so you cannot use their APIs - we obviously need it to use APIs in monaco-languageclient
• they are required to be installed by a client - we don't want it, we want to install our packages providing APIs similar to monaco-editor-core, e.g. @typefox/monaco-editor-core

[nikeee]

Two drawbacks when using a devDependency:

• You are forced to use the specified version. This may conflict with other libraries used like react-monaco-editor.
• It only gets installed if you develop this package. When using this library no devDependency is installed.
  See: https://stackoverflow.com/a/22004559

When using a peerDependency, you also get a warning when the required package is not installed.