Adding contributor into README.
Proofread and edited chapter 1. Also fixed some typos.
Updated terms in README.md
Chapter 5 80% translated. Jokes are not translated yet.
Adding folder for Dutch
Editing chapter 18.
Finished translating chapter 5. Jokes are left untranslated for now.
Merged latest upstream with Indonesian chapter 5 translation.
id-src. hangman.py - not complete
id-chapter8
id. update format chapter title: in capital letter for chapter 3,4,7,8
Merge pull request #29 from addianto/master

[ID] Chapter 5 translation
Merge pull request #30 from bbn-bernard/master

id-chapter8
Merge pull request #31 from alfredocarella/master

Partial translation of "es_chapter6.txt"
Merge branch 'master' of github.com:asweigart/inventwithpython3rded
Chapter 19 edits
Chapter 20 edits
Adding folder for Serbian.