chore: add PR template

.github/PULL_REQUEST_TEMPLATE/mnp.md

@@ -0,0 +1,30 @@
+<!--
+
+PULL REQUEST TEMPLATE FOR MAINTAINERS ONLY.
+
+https://github.com/go-acme/lego/master...branch?quick_pull=1&title=Add+DNS+provider+for+&labels=enhancement,area/dnsprovider&template=mnp.md
+
+--!>
+
+- [ ] adds a description to your PR
+- [ ] have a homogeneous design with the other providers
+- [ ] add tests (units)
+- [ ] add tests ("live")
+- [ ] add a provider descriptor
+- [ ] generate CLI help, documentation, and readme.
+- [ ] be able to do: _(and put the output of this command to a comment)_
+  ```bash
+  make build
+  rm -rf .lego
+
+  EXAMPLE_USERNAME=xxx \
+  ./dist/lego -m [email protected] --dns EXAMPLE -d *.example.com -d example.com -s https://acme-staging-v02.api.letsencrypt.org/directory run
+  ```
+  Note the wildcard domain is important.
+- [ ] pass the linter
+- [ ] do `go mod tidy`
+
+Ping @xxx, can you run the command (with your domain, email, credentials, etc.)?
+
+Closes #
+