E&Js: Finish setting up the resource page(s) for the chronological index

[dorothyyeager]

User story
As an internal stakeholder or outside legal consultant, I need to see the explanation and justification for Commission regulations to do proper legal analysis of them.

Background:
In previous issues, we worked on the citation index. The other main index for the E&Js is the chronological listing of them. (Currently these pages are linked at https://transition.fec.gov/law/cfr/ej_toc.shtml.) This process will work much like the citation index.

Work plan
We need to create the tables in word (done in #2568), update the links (done in #2617), turn into HTML blocks (#2723) and then populate a page that is set up in Wagtail. This task is to set up the pages that will have the html blocks inserted into them.

Completion criteria:

• Finalize the main page for the chronological index
• Create placeholders for the html indexes

[dorothyyeager]

After consulting with @JonellaCulmer for how to make our MVP have the best u/x, we'll go with an intro page that links to the various decade pages. I've saved that draft.

[dorothyyeager]

Thanks to @JonellaCulmer, we've set up the resource pages for these index tables and have figured out the way to do the html styling for them. Closing this issue and we'll move on to #2723 in the next sprint.