Add:
        templates/developers.html
                -Update the developers page with an "under construction"
                message.

        static/sass/developers.sass
                -Add a bare-bones stylesheet for the developers page.

Add:
    templates/index.html
        -Add compartmental `div` structure for the advanced-search form.

    static/sass/index.sass
        -Add layout style rules to the advanced-search form.

    app.py, templates/(about, developers).html
        -Add `Flask` routes and skeleton files for pages to be developed later.

Ref:
    static/js/index.js
        -Substitute some verbose `JavaScript` calls with their `jQuery`
        equivalents.