docs: fixup CHANGELOG links

CHANGELOG.md

@@ -9,19 +9,19 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 
-- ([#167](https://github.com/stac-utils/stac-task/issues/167)) Adds workflow-level
+- ([#167](https://github.com/stac-utils/stac-task/pull/167)) Adds workflow-level
   options to the ProcessDefinition object in a new `workflow_options` field. They are
   combined with each task's options, giving precedence to the task options on conflict.
-- ([#167](https://github.com/stac-utils/stac-task/issues/167)) Adds a `workflow_options`
+- ([#167](https://github.com/stac-utils/stac-task/pull/167)) Adds a `workflow_options`
   property to the `Task` class that returns the `workflow_options` dictionary from the
   `ProcessDefinition` object.
-- ([#167](https://github.com/stac-utils/stac-task/issues/167)) Adds a `task_options`
+- ([#167](https://github.com/stac-utils/stac-task/pull/167)) Adds a `task_options`
   property to the `Task` class that returns the task options from the `tasks` dictionary
   in the `ProcessDefinition` object.
 
 ### Deprecated
 
-- ([#166](https://github.com/stac-utils/stac-task/issues/123)) Bare `ProcessDefinition`
+- ([#166](https://github.com/stac-utils/stac-task/pull/166)) Bare `ProcessDefinition`
   objects are deprecated in favor of arrays of `ProcessDefinition` objects.
 
 ## [0.6.0]