Update README.md: clarify that contributiontransactlegacy is required for Drupal 7 webform, not for other Drupal versions.

Only suggesting this as noted that the 'requirements' here do not match those on the Documentation and hence wonder if best just to point folk to one source of truth :-)

Very incomplete, but hopefully is a useful start.

Drupal Webform: Re-enable hook_civicrm_buildForm and comment in different situations we need alterContent and buildForm to load js scripts

Better other credits area in README.

Clarify readme.