Rename Workspace::registerOpener to ::addOpener for consistency

src/workspace.coffee

@@ -44,7 +44,7 @@ class Workspace extends Model
     @paneContainer ?= new PaneContainer({@viewRegistry})
     @paneContainer.onDidDestroyPaneItem(@onPaneItemDestroyed)
 
-    @registerOpener (filePath) =>
+    @addOpener (filePath) =>
       switch filePath
         when 'atom://.atom/stylesheet'
           @open(atom.themes.getUserStylesheetPath())
@@ -349,8 +349,6 @@ class Workspace extends Model
     if uri = @destroyedItemUris.pop()
       @openSync(uri)
 
-  # TODO: make ::registerOpener() return a disposable
-
   # Public: Register an opener for a uri.
   #
   # An {TextEditor} will be used if no openers return a value.
@@ -358,7 +356,7 @@ class Workspace extends Model
   # ## Examples
   #
   # ```coffee
-  # atom.project.registerOpener (uri) ->
+  # atom.project.addOpener (uri) ->
   #   if path.extname(uri) is '.toml'
   #     return new TomlEditor(uri)
   # ```
@@ -367,13 +365,15 @@ class Workspace extends Model
   #
   # Returns a {Disposable} on which `.dispose()` can be called to remove the
   # opener.
-  registerOpener: (opener) ->
+  addOpener: (opener) ->
     @openers.push(opener)
     new Disposable => _.remove(@openers, opener)
+  registerOpener: (opener) ->
+    Grim.deprecate("Call Workspace::addOpener instead")
+    @addOpener(opener)
 
-  # Unregister an opener registered with {::registerOpener}.
   unregisterOpener: (opener) ->
-    Grim.deprecate("Call .dispose() on the Disposable returned from ::registerOpener instead")
+    Grim.deprecate("Call .dispose() on the Disposable returned from ::addOpener instead")
     _.remove(@openers, opener)
 
   getOpeners: ->