Add digital-marketplace-ssp-content as a submodule of the project.
I have put it in a folder 'content', which seems a reasonable place for it - I've tested building a .war file for deployment and the new folder is included in the .war package.
Change name of main.html to govuk_template.html
Split styles out into template tag

Includes creation of tags folder.
Split alpha banner out into template tag
Split out cookie banner into template tag
Split out propositional_header into template tag

Includes splitting out of header_class too.
Split layout into it's own file
Split out scripts to their own template tag
Split out footer_support_links into template tag
Give phase banner real content
Use a single controller to display question pages; move question page templates into single 'QuestionPages' package.
Merge branch 'master' of github.com:alphagov/supplier-submission-portal
Merge branch 'master' into split-out-partials
Fix template name (main.html->layout.html).
Merge pull request #2 from alphagov/split-out-partials

Split out partials