Smart quotes and en dashes in markdown help

* http://smartquotesforsmartpeople.com
* Hyphens join words and separate syllables, en dashes denote a break
in a sentence – http://en.wikipedia.org/wiki/Dash
Add acronym and abbreviation markdown guidance

* The style guide refers to “abbreviations and acronyms”, we should be
consistent. All acronyms are abbreviations.
* Update the example to include some content containing an acronym
* Explain how acronyms are found within content, and what happens when
one is found. Include an `abbr` tag to illustrate the hover effect.
* Mention that the code itself isn’t displayed, it’s confusing when it
initially disappears
eg not e.g.

* Be consistent with our content style guide
Use href not data- to define a collapse target

* By including the href we get the default link styles and cursor
pointer we want
* Bootstrap defaults to using a target specified in the href of a link
Add more acronym guidance based on writing guide

* Based on
http://alphagov.github.io/inside-government-admin-guide/creating-documen
ts/markdown.html#acronyms
* Include specifics about what should be listed (plurals, not
possessives) and caveats to avoid (spaces in markdown)
* Add a second acronym to example so that markdown looks like a list
(the asterisk begins to make more sense in this context)
Data migration to fix publication unpublishing

This publication was mistakenly set to "archived" instead of being
"unpublished". This data migration corrects the unpublishing, setting up
the redirect, and also sets the edition state back to "draft",
completing the unpublishing process.
Fix a document 404ing with a redirect

www.agileplannerapp.com/boards/173808/cards/5678

it seems 2 editors started working on separate
drafts for the same content, hence there were
duplicate documents. the content lives at the
url that contains the slug with a sequence
number. hence redirecting to that location.
Remove extra guidance on acronyms

* Guidance around plurals and possessives confused users during
research session
* Copy above worked in explaining how acronym markdown behaves and how
it’s different to other types of markdown
* Extra guidance did not match out style guide (lists should have a
lead-in sentence and shouldn’t be capitalised)
Merge pull request #1675 from alphagov/AH-acronym-help

Add acronym and abbreviation markdown guidance
Merge pull request #1679 from alphagov/fix-publication-unpublishing

Data migration to fix publication unpublishing
Merge pull request #1680 from alphagov/fix-document-404ing

Fix a document 404ing with a redirect