Create extab4 plugin and fix PHP 8 warnings

update plugin.info and README

rename _open() and _close() methods

add author

remove unnecessary guards

indent of 4 spaces, instead of tab

support colspan and rowspan for odt renderer

see #19

update plugin.info

update README

set class properties later when required

use handler->plugin() instead of addPluginCall()

avoid PHP error caused by "protected" visibility of method addPluginCall() of Doku_Handler, that has changed in DokuWiki-PSR2 branch.

handle() should return false

coding style

update plugin.info

Add support for ODT plugins PDF export

Update README

change class property name pluginMode to mode

update plugin.info

Adjusted ODT code for branch redesign.

typo correction

update plugin.info, new release

add class property pluginMode

add example.txt

require WRAP plugin

html5 attributes

miscellaneous minor edit