title: Add line break via regex
body: <p>I have a quite big text file (300k lines), which I am trying to process with Sublime Text, but open to alternatives (using mac).</p>
  
  <p>I would need to add line breaks via regex matching the pattern '(1234567)' seven digits in a bracket. The text contains other content in brackets, where line breaks are not needed. I would like to split the text to each line start at the bracket:</p>
  
  <p>Source:
  lorem, Ipsum (1234567) — text of the printing and typesetting (something) 12345. lorem, Ipsum (1234567) — text of the printing and typesetting, lorem, Ipsum (1234567) — text of the printing and typesetting (something)</p>
  
  <p>Target:</p>
  
  <p>(1234567) — text of the printing and typesetting (something) 12345. lorem, Ipsum</p>
  
  <p>(1234567) — text of the printing and typesetting, lorem, Ipsum </p>
  
  <p>(1234567) — text of the printing and typesetting (something)</p>
  
  <p>Would anyone know how to do it via regex find and replace or anyone could suggest an alternative?</p>
  
  <p>Thank you!</p>
  
  <p>Edit:
  If it's easier to replace the leading (, that's also perfect.
  Target:</p>
  
  <p>1234567) — text of the printing and typesetting (something) 12345. lorem, Ipsum</p>
  
  <p>1234567) — text of the printing and typesetting, lorem, Ipsum </p>
  
  <p>1234567) — text of the printing and typesetting (something)</p>