Add package-lock.json to source control (#1393)

While reviewing #1390, I
realized that we haven’t checked in `package-lock.json` into version
control, but we explicitly ignore it currently.

[`package-lock.json` is an auto-generated manifest
file](https://docs.npmjs.com/cli/v9/configuring-npm/package-lock-json)
which is created and maintained by `npm` on every change to
`package.json`. [Having the lock file under version control is actually
recommended](https://docs.npmjs.com/cli/v9/configuring-npm/package-lock-json#:~:text=This%20file%20is%20intended%20to%20be%20committed%20into%20source%20repositories),
because in contrast to the pure `package.json` file, the lock file
captures the entire dependency tree. This aims to make builds more
reproducible, faster, and safer (due to checksums).

Note: if git commit statistics are important to us, then we can also
commit this under a separate account (e.g. some sort of bot account),
since `package-lock.json` changes are always relatively large diffs in
terms of LOC added/deleted.
<a data-ca-tag
href="https://codeapprove.com/pr/tiny-pilot/tinypilot/1393"><img
src="https://codeapprove.com/external/github-tag-allbg.png" alt="Review
on CodeApprove" /></a>

.gitignore

@@ -67,7 +67,6 @@ venv/
 
 # Node
 node_modules
-package-lock.json
 
 # Mac OS
 *.DS_Store