chore: create PULL_REQUEST_TEMPLATE.md (#1094)

Author: crowlKats

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,13 @@
+### PR Checklist
+
+- [ ] The PR title follows
+      [conventional commits](https://www.conventionalcommits.org/en/v1.0.0/)
+- [ ] Is this closing an open issue? If so, link it, else include a proper
+      description of the changes and rason behind them.
+- [ ] Does the PR have changes to the frontend? If so, include screenshots or a
+      recording of the changes.
+      <br/>If it affect colors, please include screenshots/recording in both
+      light and dark mode.
+- [ ] Does the PR have changes to the backend? If so, make sure tests are added.
+      <br/>And if changing dababase queries, be sure you have ran `sqlx prepare`
+      and committed the changes in the `.sqlx` directory.