Ok it is not a solution but debate; What you have done so far is all good in its sense but it is not in direct view of person receiving the content aka user.
A good approach would be to place the licencing information in about us or term of use/EULA section if you go down this path. These very sections of website list and detail what is what and how it impacts the user.
Make a sub heading called third party licences and list all you need to list in that section. Make the primary link public on all pages and you are good to go.
Some examples below.
Side note, if I am crafting large enough application I would always use this keeping everything tidy up in one place. I was originally motivated to adopt this approach seeing how Microsoft and other legacy companies turned page towards Open source and how they reflected the library information. Obviously they had brains who would have thought it over so there is merit by virtue.