Add simple GitHub Pull Request template based off the one for PowerShell Core (#866)

* Add simple GitHub Pull Request template based off the one for PowerShell Core

* update pr template with help for people that are not familiar with markdown

* remove powershell core specific links

* fix typo

Author: bergmeister

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,16 @@
+## PR Summary
+
+<!-- summarize your PR between here and the checklist -->
+
+## PR Checklist
+
+Note: Tick the boxes below that apply to this pull request by putting an `x` between the square brackets. Please mark anything not applicable to this PR `NA`.
+
+- [ ] PR has a meaningful title
+    - [ ] Use the present tense and imperative mood when describing your changes
+- [ ] Summarized changes
+- [ ] User facing documentation needed
+- [ ] Change is not breaking
+- [ ] Make sure you've added a new test if existing tests do not effectively test the code changed
+- [ ] This PR is ready to merge and is not work in progress
+    - If the PR is work in progress, please add the prefix `WIP:` to the beginning of the title and remove the prefix when the PR is ready