Merge branch 'prettier-html' into 'master'

__tests__/files/gmail-gmail/one/04/r_htmlContent.html

__tests__/files/gmail-gmail/one/04/s_htmlContent.html

__tests__/files/gmail-gmail/one/05/r_htmlContent.html

__tests__/files/gmail-gmail/one/05/s_htmlContent.html

__tests__/files/gmail-gmail/one/06/r_htmlContent.html

__tests__/files/gmail-gmail/one/07/r_htmlContent.html

__tests__/files/gmail-gmail/one/09/r_htmlContent.html

__tests__/files/gmail-gmail/one/09/s_htmlContent.html

__tests__/files/gmail-gmail/one/11/r_htmlContent.html

__tests__/files/gmail-gmail/one/11/s_htmlContent.html

__tests__/files/gmail-gmail/one/12/r_htmlContent.html

__tests__/files/gmail-gmail/one/17/r_htmlContent.html

__tests__/files/gmail-gmail/one/17/s_htmlContent.html

__tests__/files/gmail-gmail/one/18/r_htmlContent.html

__tests__/files/gmail-gmail/one/18/s_htmlContent.html

__tests__/files/gmail-gmail/one/20/r_htmlContent.html

__tests__/files/gmail-gmail/one/20/s_htmlContent.html

__tests__/files/gmail-outlook/one/01/r_htmlContent.html

__tests__/files/gmail-outlook/one/01/s_htmlContent.html

__tests__/files/gmail-outlook/one/03/r_htmlContent.html