Support configurable branch (#42)

* Support configurable branch
Added github_branch parameter to config to support branch name on edit link on editable.html.
* updated version, changelog

Author: bhitney

CHANGELOG.md

@@ -14,6 +14,7 @@ Critical items to know are:
  - changed behaviour
 
 ## [master](https://github.com/vsoch/docsy-jekyll/tree/master)
+ - added support for github_branch (default 'master') in config (0.0.22)
  - adding support in footer to icon and link to linkedin url (0.0.21)
  - updating repository with copyright notice, google analytics bug fix (0.0.2)
  - fixing link to repository in about.md (0.0.19)

VERSION

@@ -1 +1 @@
-0.0.21
+0.0.22

_config.yml

@@ -32,6 +32,7 @@ url: "https://vsoch.github.io" # the base hostname & protocol for your site
 repo: "https://github.com/vsoch/docsy-jekyll"
 github_user: "vsoch"
 github_repo: "docsy-jekyll"
+github_branch: "master"
 
 # Optional
 twitter: vsoch

_includes/editable.html

@@ -1,4 +1,4 @@
-<a href="{{ site.repo }}/edit/master/{{ page.path }}" target="_blank"><i class="fa fa-edit fa-fw"></i> Edit this page</a>
+<a href="{{ site.repo }}/edit/{{ site.github_branch }}/{{ page.path }}" target="_blank"><i class="fa fa-edit fa-fw"></i> Edit this page</a>
 <a href="{{ site.repo }}/issues/new?labels={% if page.editable %}{{ page.editable }}{% else %}question{% endif %}&title=Question:&body=Question on: {{ site.repo }}/tree/master/{{ page.path }}" target="_blank"><i class="fab fa-github fa-fw"></i> Create documentation issue</a>
 <a href="{{ site.repo }}/issues/new" target="_blank"><i class="fas fa-tasks fa-fw"></i> Create project issue</a>
 <!-- this will parse through the header fields and add a button to open