Ignore `javascripts` directory comes from gh-pages
Change storategy of Indent

`indent()` now insert appropriate number of spaces
Previously, `indent()` insert fixed number of spaces (say 4 e.g.)
but now, it will be calculated from the current caret position.

Example (| indicate caret, _ indicate space)

-   Previously

        1.|____This is a test

-   Now

        1.|__This is a test

**This feature only works on single line indent**
Change the constructor arguments of AutoIndenty

The storategy of Indenty changes make constructor argument changes.
Now arguments of AutoIndenty follow the one of Indenty

Previous:
    AutoIndenty(textarea, tabString)
Now:
    AutoIndenty(textarea, expandTab, indentLevel)
Update document
Fix indentLeve issue
Add Ctrl+Z/Ctrl+Shift+Z hook to use Caretaker

Hit Ctrl+Z/Ctrl+Shift+Z call `undo` and `redo` method of
caretaker
Regulate caretaker behavior for indent