release-notes.d: cleanup README and add an example for intermediate notes

Signed-off-by: Allen Bai <[email protected]>

Author: Allen Bai

release-notes.d/README

@@ -1,13 +1,8 @@
 # Fedora CoreOS Release Note
 
-This directory stores the Fedora CoreOS release note yaml snippets which will be picked up by
-`fedora-coreos-releng-automation/coreos-release-note-generator` [1] script to produce the final
-`release-notes.yaml` for a release. After `release-notes.yaml` has been generated / updated,
-all snippets under `release-notes.d` are expected to be cleaned up for future release notes.
+This directory stores the Fedora CoreOS release note yaml snippets which will be picked up by `fedora-coreos-releng-automation/coreos-release-note-generator` [1] script to produce an intermediate `release-notes.yaml` which contains a `next-release` field. Then the intermediate yaml file would be updated to reflect the actual build ID for a release. After `release-notes.yaml` has been generated and updated, snippets under `release-notes.d` are expected to be cleaned up for future release notes.
 
-Release notes will be organized according to the origin of the change, i.e. the project name.
-Other miscellaneous changes will be stored under `miscellaneous`. Therefore, the schema
-of each yaml snippet is designed as follows:
+Release notes will be organized according to the origin of the change, i.e. the project name. Otherwise miscellaneous changes will be stored under `miscellaneous`. Therefore, the schema of each yaml snippet is designed as follows:
 
 ```yaml
 # Each yaml file consists of a list of dictionaries which looks like this
@@ -16,14 +11,36 @@ of each yaml snippet is designed as follows:
   body (optional): xxxxx
 ```
 
-The final rendered version is expected to be:
+An example intermediate `release-notes.yaml` generated from `release-notes.d` is expected to be:
+```
+- next-release:
+    coreos-assembler:
+      - add a new sub-command that automates xxx (details)
+      - fix a bug that result in https://github.com/coreos/fedora-coreos-tracker/issues/xxx
+    miscellaneous:
+      - introduce a new config file to facilitate xxx workflow (details)
+- 32.20200706.3.0:
+    afterburn:
+      - add support for platform xxx
+- 32.20200620.1.0:
+    ignition:
+      - fix a minor issue https://github.com/coreos/fedora-coreos-tracker/issues/xxx
+```
 
+The final rendered version is expected to be:
 ```
-32.20200715.3.0:
- - coreos-assembler:
-    add a new sub-command that automates xxx (details)
- - miscellaneous:
-    introduce a new config file to facilitate xxx workflow (details)
+- 32.20200715.3.0:
+  - coreos-assembler:
+    - add a new sub-command that automates xxx (details)
+    - fix a bug that result in https://github.com/coreos/fedora-coreos-tracker/issues/xxx
+  - miscellaneous:
+    - introduce a new config file to facilitate xxx workflow (details)
+- 32.20200706.3.0:
+    afterburn:
+      - add support for platform xxx
+- 32.20200620.1.0:
+    ignition:
+      - fix a minor issue https://github.com/coreos/fedora-coreos-tracker/issues/xxx
 ```
 
 _Note_: Clicking on the `details` button will show the body of the release note item.