updates output formats and asciidoctor users

- minor spelling and punctuation changes
- URL display clean up

@mgreau Awesome! I just had little, minor changes. I've listed most of the changes I made below so that, hopefully, you can skim through the pull request quickly and decide which changes you want to merge or discard. @mojavelinux will also take a look at the slides soon.

*General changes*
- stripped `http` from displayed URLs, makes the slides look cleaner and saves slide space
- slight spelling and punctuation changes to the speaker notes
- adjusted some punctuation and spellings to English conventions since this will apply to the majority of audience members; used 
Merriam-Webster Dictionary

*Slide 2*
- added URL for twitter handle
- changed hashtag before adeditor to Unicode so `[detail]` markup isn't escaped too early

*Slide 10 and Slide 21*
- The blockquote text wasn't displaying in my browser (Chrome) so I changed the shorthand quote syntax to the longform syntax; HOWEVER, they did display in Firefox, so I changed them back to your original syntax. It turns out there might be a bug in Chrome or on my system that messes up the font loading of blockquotes. When I turned off the font using the dev tools, the quote text showed up. I'll follow up on this issue.
- Torvald to Torvalds
- RedHat to Red Hat

*Slide 13*
- removed ``i.e. backends'' (this terminology will be (has been?) deprecated and changed to converter)
- general trend seems to be to write HTML5 as a closed compound word (i.e. no space between HTML and 5)
- changed e-Book to e-book; according to the Merriam-Webster Dictionary (which is the dictionary a lot of American publishers use) lowercases the ``b''
- changed ePub to EPUB and mobi to MOBI, file formats are capitalized
- added KF8 (asciidoctor-epub, which will be released this week creates KF8, the new Kindle format that replaces MOBI. MOBI has reached its end of life. asciidoctor-epub also outputs EPUB 3 that will be backwards compatible with EPUB 2 readers.)
- uppercased first letter of first word after each bullet to create visual consistency 

*Slide 15*
- Changed specifications to standards
- Added a few other users
- NFJS stands for No Fluff Just Stuff. The magazine is written using Asciidoctor and output to PDF and EPUB using asciidoctor-pdf and asciidoctor-epub
- Neo4j uses Asciidoctor.js for their documentation
- changed Github to GitHub

*Slide 17*
- cleaned up URL display