Fluid 5439: Add LocalizationInThePreferencesFramework.md

This pull request adds LocalizationInThePreferencesFramework.md and its associated image. The pull request does not update the README.md with a link to the new page. We don't yet have a section in the table of contents for Preferences. Other outstanding pull requests are adding to README.md (such as https://github.com/fluid-project/infusion-docs/pull/13). We can update this pull request once others are in and we have a Preferences structure in README.md to add to.
Shall we leave this as is until we decide on a strategy of framework API links?