add Magento v1.x development best practice book
Merge branch 'develop' into feature/magento-v1.x-dev-best-practices
prefix minor changes
addd content for magento basics
reorganize chapter structure
modify prefix
TOC update for CHAPTER 3. BUILD EXTENSION and CHAPTER 4. ADVANCED TOPIC
TOC update: CHAPTER 5. WORKING WITH MAGENTO
update TOC: CHAPTER 6. FREQUENTLY SEEN MISTAKES