Implement libraries.io support for pre-commit

• https://github.com/librariesio/libraries.io/blob/master/docs/add-a-package-manager.md
• can likely use all-repos.json and maybe(?) take some inspiration from the go implementation for libraries.io (since the distribution mechanism is similar)

Start with the libraries.io add-a-package-manager documentation and compare the existing Go implementation for libraries.io. Inspect all-repos.json to determine how it could support the integration. Done means pre-commit has working libraries.io support, though the issue does not identify specific files or tests.