bbcode documentation: BBCodes.md complete rewrite
bbcode documentation: BBCodes.md complete rewrite

- Switched to table display to put BBCodes and result side-by-side
- Added all missing BBCodes

fabrixxm/friendica,fabrixxm/friendica,friendica/friendica,tobiasd/friendica,friendica/friendica,fabrixxm/friendica,fabrixxm/friendica,friendica/friendica,annando/friendica,fabrixxm/friendica,annando/friendica,friendica/friendica,tobiasd/friendica,tobiasd/friendica,annando/friendica,tobiasd/friendica,friendica/friendica,tobiasd/friendica,annando/friendica,annando/friendica