support pnpm

[mrooding]

Is your feature request related to a problem? Please describe.
After !1013 the repository wouldn't work anymore with pnpm

Describe the solution you'd like
Support using pnpm out of the box

Describe alternatives you've considered
N/A

Additional context
I was able to get pnpm to work by modifying a few things. However, unfortunately these changes break support for npm. I'm not sure whether there's a compatible method that supports both npm and pnpm. If there's not, maybe it's good enough to include support for package managers in the read me.

npm error code EUNSUPPORTEDPROTOCOL
npm error Unsupported URL Type "workspace:": workspace:../preload/

pnpm workspace support
First of all, the workspaces block in the root package.json isn't supported:

 WARN  The "workspaces" field in package.json is not supported by pnpm. Create a "pnpm-workspace.yaml" file instead.

I created a pnpm-workspaces.yaml with the following content:

packages:
  - "packages/*"

workspaces dependencies
I had to modify the way the workspaces are included as dev or regular dependencies. Instead of the "*" value, I had to use the `"workspace:../path" notation.

E.g.: "@vite-electron-builder/main": "*" became "@vite-electron-builder/main": "workspace:./packages/main/"

[cawa-93]

I don't really understand what exactly you are suggesting. The things you described are natural incompatibilities between the two tools.
NPM expects workspace descriptions in a package.json, while PNPN expects them in a separate file.
PNPM does support a special protocol, NPN does not.

Supporting all versions of all tools is not a goal for this template. And if you want to switch one tool to another, you have to make small twiks.