Add to *.lock

[ghost]

Reasons for making this change:

TODO
Maybe it is not always the best idea to put the yarn.lock file in your repository.
Links to documentation supporting these rule changes:

TODO

If this is a new template:

• Link to application or project’s homepage: TODO

[luftywiranda13]

But, ignoring lock files by listing them in .gitignore is harmful

https://github.com/luftywiranda13/remove-lockfiles#why
facebook/create-react-app#2014 (comment)

[shiftkey]

@ImDavaloper please provide more context for this change. As @luftywiranda13 mentioned, some lock files that should be committed will be caught by this rule...

[shiftkey]

From the docs:

All yarn.lock files should be checked into source control (e.g. git or mercurial). This allows Yarn to install the same exact dependency tree across all machines, whether it be your coworker’s laptop or a CI server.