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