add 'width' parameter to 'figure' shortcode
Document manual breakpoint of .Summary

The use of <!--more--> to set the breakpoint for the generated page summary is mentioned in a release note, but not in the doc itself.

Very useful - and it leaves the formatting in place.
Minor proofreading corrections to Hugo docs

- Add backticks and commas where necessary
- Remove some trailing whitespace
- Add front matter example in TOML
- Fix typo in one of the tags in Showcase
- Add 多说 (Duoshuo) as an alternative to Disqus
- Use internal links (i.e. without gohugo.io) where possible
- Use a colon to set off an example
- Change "it's" to "its" where appropriate
- Use typographical (i.e. curly) apostrophe on the front page
  where appropriate
- Capitalize "Github" as "GitHub"
added docs for 'intersect' and 'in' template functions
Add nil-check to Intersect

The Intersect template-method would fail if one or both of the lists were nil (post vs page; post has tags, page has not).

This commit adds a nil-check and returns an empty result if any of the inputs are nil.

See #537
Fix spf13/hugo#467. RSSLink now point to index.xml
Make First accept any int

TOML and YAML handles integers differently, creating issues when using integer values from configuration or front matter in the First template function.

This currently works in YAML (parses into int), but not in TOML (parses into int64).

This commit modifies First so it accepts any int.

Fixes #551
Copy content from archetype

Prior to this commit only metadata were copied from archetype on content creation.

This commit includes the content if set in archetype. This is useful in situations with similar page structure.

Fixes #556
Set Content-Type for livereload.js

The Content-Type was not set for livereload.js and was interpreteted by the browser as text/plain.

This commit sets it to application/javascript.

Fixes #562