Modified the format of README.md

Modified the format of deploy_guide.md

Modified the format of quick_start.md

Modified the format of  RocketMQ_Example.md

Modified the format of architecture.md

Modified the format of features.md

modify the format of concept.md

* Modify the article layout format

* Update Design_Store.md

[RIP-9] Add the system configuration option doc: Direct ByteBuffer memory size

[RIP-9] Add doc of best practice for broker 

[RIP-77]Modify the last paragraph and rid of punctuation between each section number and title

 JVM Options :A simple JVM configurations looks like this	改为A simple JVM configuration is as follows