add github btn

adjust style
Update 05-getting-started.md

修改别字.
Merge pull request #15 from sunorry/patch-1

Update 05-getting-started.md
add sunorry
更新链接
添加返回目录在页尾
Merge pull request #16 from zhuochun/gh-pages

添加返回目录在页尾
add zhuochun
fix #17
Merge branch 'gh-pages' of github.com:island205/HelloSea.js into gh-pages
typo
Merge pull request #19 from chekun/patch-1

typo
add Che Kun
remove whitespace
add some word
add some word
fix broken link