Merge pull request basarat#452 from ccouzens/master

Fix link to truthy Javascript chapter

Author: basarat

SUMMARY.md

@@ -9,7 +9,7 @@
  * [this](docs/javascript/this.md)
  * [Closure](docs/javascript/closure.md)
  * [Number](docs/javascript/number.md)
- * [Truthy](docs/tips/truthy.md)
+ * [Truthy](docs/javascript/truthy.md)
 * [Future JavaScript Now](docs/future-javascript.md)
  * [Classes](docs/classes.md)
  * [Classes Emit](docs/classes-emit.md)