Update PULL_REQUEST_TEMPLATE.md

With the automated review, we don't need most of what the previous template mentioned. Just explain the general process to them and wrap it in an HTML comment.

.github/PULL_REQUEST_TEMPLATE.md

-Please provide the following information:
+<!--
+Your pull request will be reviewed automatically and by a human.
 
- - Link to your code repository:
- - Link to the tags page with at least one [semver](http://semver.org) tag: 
+Please ensure the automated reviews pass. Follow the instructions provided, if necessary.
+You can speed up the process by [running some tests locally](https://packagecontrol.io/docs/submitting_a_package#Step_7).
 
-Also make sure you:
+In general, make sure you:
 
- 1. Used `"tags": true` and not `"branch": "master"` ([versioning docs](https://packagecontrol.io/docs/submitting_a_package#Step_4))
- 2. Ran the tests ([tests docs](https://packagecontrol.io/docs/submitting_a_package#Step_7))
+ 1. Used `"tags": true` and not `"branch": "master"` 
+    ([versioning docs](https://packagecontrol.io/docs/submitting_a_package#Step_4))
+ 2. Added a readme to your repository so that users (and reviewers) 
+    can understand what your package provides.
+ 
+You may proceed with a short description of what the package does and, 
+in case a similar package already exists, 
+why you believe it is needed
+below this line. -->