Issue template: Add "emerging platform" template

Add a new template that does not include all the steps to generate boot
images. We'll use that template for "emerging" platforms where we don't
have full support yet.

This will help adding new platforms to Fedora CoreOS without imposing an
ever increasing burden on our release pipeline and cloud storage by
creating more (mostly) duplicated boot images.

.github/ISSUE_TEMPLATE/implementing-new-emerging-platform.md

@@ -0,0 +1,41 @@
+# Implementing a new emerging platform
+
+This template is a simplified version of the
+[full template](https://github.com/coreos/fedora-coreos-tracker/blob/main/.github/ISSUE_TEMPLATE/implementing-new-platform.md)
+that only includes what is strictly needed to get initial support for a new
+platform in Fedora CoreOS. This simplified version notably does not include the
+steps needed to add new boot images to the release process.
+
+Platforms added via this process are labelled "emerging" and users will have to
+get boot images for them by converting existing images in the right format and
+changing the `ignition.platform.id=<platform>` command line parameter.
+
+This process will be documented using `guestfish` as an example.
+
+## During Development
+
+Create PRs addressing the following:
+
+- [ ] [Ignition](https://github.com/coreos/ignition/) ([example PR](https://github.com/coreos/ignition/pull/918))
+  - [ ] Add userdata fetch
+  - [ ] If the platform supports it (unlikely), add userdata deletion
+- [ ] [Afterburn](https://github.com/coreos/afterburn/) ([example PR](https://github.com/coreos/afterburn/pull/451))
+  - [ ] (Cloud Only) Add relevant attributes
+  - [ ] (Cloud Only) Add SSH key support if available
+  - [ ] (Cloud Only) Add hostname support if available
+  - [ ] (Cloud Only) Add check-in if needed (unlikely)
+- [ ] [fedora-coreos-docs](https://github.com/coreos/fedora-coreos-docs) ([example PR](https://github.com/coreos/fedora-coreos-docs/pull/377))
+  - [ ] Add a `provisioning-<platform>.adoc` that walks through how to setup the new platform
+  - [ ] Add an entry in the `modules/ROOT/nav.adoc` that points to new documentation
+- [ ] (Optional but recommended) Add support for the platform to [kola](https://github.com/coreos/coreos-assembler) to simplify testing
+- Create or ask for a new upstream releases for:
+  - [ ] Ignition
+  - [ ] Afterburn
+- Wait for new images with updated Ignition and Afterburn to reach stable then
+  merge documentation with `guestfish` commands:
+  - [ ] fedora-coreos-docs
+
+## At Release
+
+There are no "At Release" steps as we do not produce new boot images for
+emerging platforms/

.github/ISSUE_TEMPLATE/implementing-new-platform.md

@@ -2,7 +2,7 @@
 
 ## During Development
 
-Create PR's addressing the following:
+Create PRs addressing the following:
 
 - [ ] [Ignition](https://github.com/coreos/ignition/) ([example PR](https://github.com/coreos/ignition/pull/918))
   - [ ] Add userdata fetch