code: function setContent( content, options ) {
      options = getOptions( options );
  
      return vscode.workspace.openTextDocument( {
              language: options.language
          } )
          .then( doc => vscode.window.showTextDocument( doc ) )
          .then( editor => {
              let editBuilder = textEdit => {
                  textEdit.insert( new vscode.Position( 0, 0 ), String( content ) );
              };
  
              return editor.edit( editBuilder, {
                      undoStopBefore: true,
                      undoStopAfter: false
                  } )
                  .then( () => editor );
          } );
  }
docs: Returns a promise that will provide a tet editor with given `content`.
  
  @param {String} content
  @param {Object} [options] Config object.
  @param {String} [options.language='text'] Indicates what language should the editor use.
  @param {String} [options.caret='^'] Character used to represent caret (collapsed selection).
  @param {Object} [options.anchor]
  @param {String} [options.anchor.start='['] Selection anchor open character.
  @param {String} [options.anchor.end=']'] Selection anchor close character.
  @param {Object} [options.active]
  @param {String} [options.active.start='{'] Selection active part open character.
  @param {String} [options.active.end='}'] Selection active part close character.
  @returns {Promise<TextEditor>}