Update copyright date

Update CHANGELOG and history

Update CHANGELOG and history

v2: Introduce show_overlay_excerpt and document  (#1436)

Make excerpts optional in header overlay

Some posts and some header images don't lend themselves well to
displaying the excerpt in the overlay. Make this optional by
introducting a new boolean variable:

`page.header.show_overlay_excerpt`

Set it to implicitly default to `true` so existing users are unaffected by
testing explicitly for "!= false".

This can be enabled globally for a site by changing the default to `false`
in the local _config.yml, or per page by specifying the value in front
matter.

Document show_overlay_excerpt variable

* Add show_overlay_excerpt variable to the Header Overlay field documentation table.

Close #1429 

Release 4.8.1 💎

Update CHANGELOG and history

Update Lunr (#1419)

* Update Lunr to 2.1.5
* Remove colons from query string

Fixes #1419 

Update CHANGELOG and history

Add Japanese localized UI text strings

Add Japanese translation of ui-text (#1411)

Update CHANGELOG and history

Update CHANGELOG and history

Add `author.name`

Merge branch 'master' of https://github.com/mmistakes/minimal-mistakes

Feature: Adding linkback functionality Author avatar & Name (#1386)

* adding linkback funct to author avatar & nm

* rm author_class; change linkback var to home; updating config docs

Update copyright

Move zh-HK fix under Bug Fixes in CHANGELOG

Remove beta note

Release 4.8.0 :gem:

Fix open-ended dependency warnings