Draft of the JavaScript style guide for Ember

Related to #9849

- [x] use spaces after the keyword in block statements (#10073)
  - [x] `requireSpaceBeforeKeywords`
  - [x] `requireSpaceAfterKeywords`
- [x] use spaces before block statements (#10095)
  - [x] `requireSpaceBeforeBlockStatements`
- [x] use spaces in ternary conditional statements (#10097)
  - [x] `requireSpacesInConditionalExpression`
- [x] use spaces in functional declarations (#10098)
  - [x] `requireSpacesAfterClosingParenthesisInFunctionDeclaration`
- [x] disallow space before () in call expressions (#10099)
  - [x] `disallowSpacesInCallExpression`
- [ ] disallow newline before opening curly brace of all block statements
  - [ ] `disallowNewlineBeforeBlockStatements`
- [ ] disallows placing keywords on a new line
  - [ ] `disallowKeywordsOnNewLine`
- [ ] disallow block statements from beginning and ending with 2 newlines
- [ ] use empty line above the specified keywords unless the keyword is the first expression in a block statement
- [ ] disallow empty block statements
- [ ] disallow space after opening array square bracket and before closing
- [ ] disallow space after opening round bracket and before closing
- [x] disallow spaces before semicolons (#10084)
  - [x] `disallowSpacesBeforeSemicolons`
- [ ] requires blocks to begin and end with a newline (#10100)
  - [ ] `requireBlocksOnNewline`

cc @rwjblue 
would it be worth adding `bad` like you do below?

```javascript
// good
var foo = {};
// bad
var foo = {} ;
```