Get rid of 4 meta programming chapter for now
Improve maps description
Link to IRC channel
fixing a typo
Merge pull request #236 from guedes/patch-1

fixing a typo
Merge pull request #235 from Aupajo/patch-1

Link to IRC channel
Typo, grammar, and style fixes in Sigils
Merge pull request #237 from alco/typos

Typo, grammar, and style fixes in Sigils
Fix code highlighting in page 10 of getting started docs
Merge pull request #238 from dimroc/master

Fix code highlighting in page 10 of getting started docs
Fix typo in Chapter 6

The code sample of `String.valid?/1` lacks a `<`.
Merge pull request #239 from teeceepee/patch-1

Fix typo in Chapter 6
Function clause without body => function head
Merge pull request #240 from ericmj/function-head

Function clause without body => function head
Update Mix docs to talk about hex
Translate into japanese(1 Interactive Elixir)
Translate into japanese(2 Basic types)
Translate into japanese(3 Basic operators)
Translate into japanese(4 Pattern matching)
Translate into japanese(5 case, cond and if)