Fixed annoying scrolling 'jump' issues on post page
Tweaked editing textarea for posts:
- auto scroll to top for textarea scroll bar,
- auto scroll browser scroll bar to start of textarea,
- set cursor to start of textarea,
- removed textarea.style.height to auto.
- auto scroll to top for textarea scroll bar,
- auto scroll browser scroll bar to start of textarea,
- set cursor to start of textarea,
- removed textarea.style.height to auto.