[3.7] bpo-33488: Satisfy markdownlint for the pull request template. (GH-6786)

./.github/PULL_REQUEST_TEMPLATE.md:8: MD031 Fenced code blocks should be
surrounded by blank lines
./.github/PULL_REQUEST_TEMPLATE.md:10: MD031 Fenced code blocks should
be surrounded by blank lines
./.github/PULL_REQUEST_TEMPLATE.md:19: MD031 Fenced code blocks should
be surrounded by blank lines
./.github/PULL_REQUEST_TEMPLATE.md:21: MD031 Fenced code blocks should
be surrounded by blank lines.
(cherry picked from commit 5cd22cf2097a6dd209999cf97858d54564a3be87)

Co-authored-by: Eitan Adler <grimreaper@users.noreply.github.com>
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 0f238d0..402e528 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -1,8 +1,10 @@
 !!! If this is a backport PR (PR made against branches other than `master`),
 please ensure that the PR title is in the following format:
+
 ```
 [X.Y] <title from the original PR> (GH-NNNN)
 ```
+
 Where: [X.Y] is the branch name, e.g. [3.6].
 
 GH-NNNN refers to the PR number from `master`.