Updating README file to be a Markdown file that follows current Drupal best...
requested to merge issue/views_block_placement_exposed_form_defaults-3230990:3230990-update-doco-for into 8.x-1.x
Updating README file to be a Markdown file that follows current Drupal best practice - https://www.drupal.org/docs/develop/managing-a-drupalorg-theme-module-or-distribution-project/documenting-your-project/readmemd-template
Closes #3230990