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.
Regarding links to function APIs, I don't think we want to keep links back into the old docs. We anticipate the generated API docs, so we've been putting in links to not-yet-existing-but-anticipated markdown pages, e.g. "fluid.messageResolver.md"