Removing node_modules

The node_modules/ directory is typically not committed to a repository.

The basic reason behind this is that there are a lot of files here, and having to push a new commit every time a dependency of a dependency changes is frustrating, sometimes confusing, eats up bandwidth, and shows large changesets in MRs when it was a small change.

Instead, commit the package.json and the package-lock.json files -- these together describe the contents of the node_modules/ directory perfectly, so any developer can install it with a simple npm install (or npm ci).