New features for jekyll!

Add New features

## New features
1. export ssg type and root path of ssg are get from settings, not every time export.
2. tile, tags, and time are auto-added into the frontmatters.
3. When export to Jekyll, all of the note under the folders and it sub-folders and sub-sub-folders and sub-sub-sub...folders can all be export.
4. When export to Jekyll, the note with tags "settings" will write to dist descibed by the first line of the note, while the firstline will delet when writing.
5. When export to Jekyll, the note with tags "pages" will write as page, the distpath are no longer "_posts" but the path of notebooks.