updated Readme

Author: loiane

README.md

@@ -7,7 +7,6 @@ Book link - first edition:
   - [Packt](https://www.packtpub.com/application-development/learning-javascript-data-structures-and-algorithms)
   - [Amazon](http://www.amazon.com/gp/product/1783554878/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1783554878&linkCode=as2&tag=loiagron-20&linkId=7VBQ7OMJ47XY7MUV)
 
-
 ### List of Chapters:
 
 * 01: [JavaScript: a quick overview](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter01)
@@ -16,7 +15,7 @@ Book link - first edition:
 * 04: [Queues](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter04)
 * 05: [Linked Lists](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter05)
 * 06: [Sets](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter06)
-* 07: Dictionaries and Hashes
+* 07: [Dictionaries and Hashes](https://github.com/loiane/javascript-datastructures-algorithms/tree/second-edition/chapter07)
 * 08: Trees
 * 09: Graphs
 * 10: Sorting and searching algorithms
@@ -28,7 +27,6 @@ Book link - first edition:
 
 Please refer to [this link](https://github.com/loiane/javascript-datastructures-algorithms/tree/master)
 
-
 ### Found an issue or have a question?
 
 Please create an [Issue](https://github.com/loiane/javascript-datastructures-algorithms/issues) or [Pull Request](https://github.com/loiane/javascript-datastructures-algorithms/pulls)