`maxGraph` was using `lerna` v4 to build and only used its "build
workspaces" support, not the "publishing" support as we only published a
single package and it is done manually, without using `lerna`.
The support for packages in `lerna` was removed in version 7. See
https://github.com/lerna/lerna/releases/tag/7.0.0 and
https://lerna.js.org/docs/legacy-package-management.
So, start using npm workspaces as we don't need to manage the publishing
of several packages for now.
This will allow to do more reproducible builds by locking dependencies
with a `package-lock.json` file. This didn't work well with `lerna` v4
and had been disabled.
We use a recent TypeScript version to build maxGraph but applications
that integrates it may be forced to use old TypeScript versions.
We never explain what is the minimum TypeScript version requires to use
`maxGraph`. The changes proposed here are a first step to make this
information available.
It is only informative for now (mentioned in the README) and the minimum
TypeScript version is tested in the `ts-support` package (part of the
'build' GitHub workflow).
Thomas Bouffard