Add streamlit index.html overrides in dockerfile

[brynpickering]

Another attempt to improve SEO (linked to #111)

Summary of changes in this pull request

• Dockerfile command added to modify the streamlit package at its source (inside the image), to change values in the index.html file as mentioned in this forum thread.

Contributor checklist

• Licensing information to new or modified files has been added (SPDX header, REUSE.toml, etc.).
• By contributing I agree to make my contributions available under the repository's MIT license and the data generated under the repository's CC-BY-4.0 license.
• I have added myself to the list of contributors in AUTHORS.md (if applicable).

Reviewer checklist

• Test(s) added to cover contribution
• Changelog updated