Move note about screenshots up in the PR template (#8501)

Marshall Bowers created 

This PR rearranges the PR template to move the line about including
screenshots or media up underneath the `Added/Fixed/Improved` section.

This makes it easier to delete one section or the other depending on
what kind of change you're making.

Release Notes:

- N/A

Change summary

.github/pull_request_template.md | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

Detailed changes

.github/pull_request_template.md 🔗 

@@ -4,8 +4,8 @@ Release Notes:
 
 - Added/Fixed/Improved ... ([#<public_issue_number_if_exists>](https://github.com/zed-industries/zed/issues/<public_issue_number_if_exists>)).
 
+Optionally, include screenshots / media showcasing your addition that can be included in the release notes.
+
 **or**
 
 - N/A
-
-Optionally, include screenshots / media showcasing your addition that can be included in the release notes.