docs: add PR template and clarify AI usage in pr descriptions

.github/pull_request_template.md

@@ -0,0 +1,31 @@
+<!--
+Read https://github.com/quickshell-mirror/quickshell/blob/master/CONTRIBUTING.md before opening a PR.
+
+Failing to do so may result in a ban from opening PRs.
+-->
+
+### Describe your changes
+<!-- High level overview of what you are changing and why. AI may not be used to write this. -->
+
+### Details and descisions
+<!--
+Put details of why you took a given approach to problems here if its not obvious.
+Reviewing PRs is easier if we don't have to reverse engineer your reasoning.
+
+Consider if things you put here should be code comments instead.
+
+If an AI was heavily used to make the change and its context might be useful,
+put it in a spoiler under your own reasoning.
+-->
+
+### Open concerns
+<!-- Anything you're not sure of or want help with? -->
+
+### Participation
+<!--
+With the advent of AI, we get a lot more drive-bys that don't care about participating
+in a traditional review process, and just want to get a change in.
+
+If you care about your code or learning how the project works to contribute in the future,
+please say so. If not, we'll assume you don't particularly care.
+-->