README cleanup

Not sure if the line "Make sure you've created CLs with any imported GH changes." under Troubleshooting needs to stay or not.
Link mistake
Markup fixes so there are no parsing errors.
Add doctype to preview template

Adding <!DOCTYPE html> because I was getting the browser user agent styles applied instead of the DCC styles over in /multidevice.

StackOverflow: http://stackoverflow.com/questions/11348727/why-does-user-agent-stylesheet-override-my-styles

Who knows what other formatting issues it may be causing.
Merge pull request #115 from pearlchen/preview-template-fix

Add doctype to preview template
Merge pull request #114 from pearlchen/patch-1

README cleanup
Merge pull request #113 from Garbee/emulation

Markup fixes so there are no parsing errors.
Merge pull request #112 from WellingGuzman/patch-1

Link mistake
protocol link
Remove duplicate shortcuts in shortcuts.html.
Add Long Resume documentation.
Merge pull request #119 from fangjue/remove_duplicate_shortcuts

Remove duplicate shortcuts in shortcuts.html.
Merge pull request #118 from fangjue/long_resume

Restore Long Resume documentation.
Thanks!
Clarifications to "Debugging With Breakpoints" and added info on async call stacks.
inspector inception docs updated. fixes crbug.com/374253
Device mode kbd shortcut

https://codereview.chromium.org/405803004
Merge pull request #120 from pearlchen/add-async-debug

Clarifications to "Debugging With Breakpoints" & added info on async call stacks
Initial commit of new emulation docs
First round of updates from feedback on intial docs.
Initial final refactor. Just a few examples to finish off and testing to do.