Add ideas board functionality

[hlashbrooke]

This is a draft PR to work on the ideas board feature outlined in #883

Closes #883

[hlashbrooke]

Features still in development:

• Character limit on submission form
• Preventing page refresh from resubmitting form
• Single post template for ideas
• Filtering and search for ideas archive
• The entire voting system

[hlashbrooke]

To do:

• Character limit on the submission form
• Single post template for ideas
• The entire voting system

[hlashbrooke]

To do:

• Character limit on the submission form
• The entire voting system

[hlashbrooke]

To do:

• The entire voting system

[hlashbrooke]

To test this PR:

• Refresh your site permalinks
• Add the following five terms to the 'Status' taxonomy in the 'Idea' post type:
  • Submitted
  • Accepted
  • In progress
  • Rejected
  • Complete
• Add the following four terms to the 'Type' taxonomy in the 'Idea' post type:
  • Tutorial
  • Lesson Plan
  • Online Workshop
  • Course
• Go to http://localhost:8888/ideas/

[hlashbrooke]

The final to-do item is to implement the actual voting UI - the HTML & CSS elements are there and the processing function is in place, but it needs the JS to make it actually happen. I'm pretty lost with how to implement the JS for this, so I'm going to need some assistance getting that across the finish line.