Add project translations for meta data keywords

[vkbo]

Summary:

When building a manuscript, the keywords were translated using the UI language rather than the project language (which can be different). This PR adds translations for the keywords to the project language files.

Related Issue(s):

Reviewer's Checklist:

• The header of all files contain a reference to the repository license
• The overall test coverage is increased or remains the same as before
• All tests are passing
• All flake8 checks are passing and the style guide is followed
• Documentation (as docstrings) is complete and understandable
• Only files that have been actively changed are committed