add demos link in js_guide
Merge branch 'master' of github.com:avoscloud/avoscloud-doc
add ios realtime push doc
Merge pull request #39 from leancloud/realtime-push

补充 离线消息推送 FAQ
Create CONTRIBUTING.md

Related issue https://github.com/leancloud/basecamp/issues/13
Added quick start link to guides.
Merge pull request #38 from lbt05/master

增加sns的xml资源
Merge pull request #40 from leancloud/feature/quick-start

Added quick start link to guides.
add chat.avosapps.com link
tweak words in push guide
add realtime ios push sample image
feat(docs): add quicks start guide

This fixes https://github.com/leancloud/avoscloud-docs/issues/182
chore: update readme
chore: `github.com/avoscloud` => `github.com/leancloud`
chore: github.com/avos => github.com/leancloud
Update bigquery_guide.md
Update bigquery_guide.md
fix sns link
fix push upload link
add avuser subclass warning