Add tags feature.

Signed-off-by: Jiahe Jou <joujiahe@gmail.com>
Use button instead of in-line detection to submit.

Signed-off-by: Jiahe Jou <joujiahe@gmail.com>
1. Add secure validation.
2. Displayw loading text before posts ready.

Signed-off-by: Jiahe Jou <joujiahe@gmail.com>