Add usage

###Add patterns to an existing .gitignore file git ignore add <file> <pattern1>[,<pattern2>,...]

Adds one or more patterns to the specified .gitignore

###Parameters

• `<file>` : the .gitignore file to populate
  

• `<pattern1>[,<pattern2>,...]` : comma separated list of pattern names to add
  

pattern names are the ones listed using git ignore list command and are case sensitive.