Describes what to do with the indentation when pressing Enter.
Variables
read onlyIndent:IndentAction
Insert new line and indent once (relative to the previous line's indentation).
read onlyIndentOutdent:IndentAction
Insert two new lines:
* - the first one indented which will hold the cursor
* - the second one at the same indentation level
read onlyOutdent:IndentAction
Insert new line and outdent once (relative to the previous line's indentation).