Update issue templates

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,16 @@
+---
+name: Bug report
+about: I think I found a bug
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+Please do report bugs you find, especially if something is calculated incorrectly, something is rejected when it should be accepted, something is accepted but should be rejected, etc.
+
+Please do not submit bug reports requesting new features.
+
+Please do not submit bug reports requesting ports to new platforms. That is a feature request.
+
+Please do not submit bug reports caused by build failures unless you are *confident* that it is a true bug and not a build configuration issue. This project isn't as easy to build as other Rust projects. Most bug reports are about really asking for help figuring out how to configure the build. `mk/cargo.sh`, `mk/install-build-tools.{sh,ps1}`, and the GitHub Actions configuration contain plenty of examples of how to build this.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,10 @@
+---
+name: Feature request
+about: No feature requests are being accepted
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+Please do not submit feature requests to this repo. I'm not accepting feature requests. Thanks!