CICD: Improve the Release Note Generation

Use .md suffix to get the files displayed as markdown.
Ignore generated artefacts.

Signed-off-by: Michael Keller <mikeller@042.ch>

.github/workflows/post-releasenotes.yml

@@ -32,5 +32,5 @@ jobs:
         repository: subsurface/nightly-builds
         token: ${{ secrets.NIGHTLY_BUILDS }}
         prerelease: false
-        files: gh_release_notes
+        files: gh_release_notes.md
         body_path: gh_release_notes

.gitignore

@@ -47,3 +47,4 @@ packaging/ios/Qt
 packaging/ios/asset_catalog_compiler.Info.plist
 appdata/subsurface.appdata.xml
 android-mobile/Roboto-Regular.ttf
+gh_release_notes.md

scripts/create-releasenotes.sh

@@ -6,7 +6,7 @@
 
 json=$(gh pr list -s merged -S "$1" --json title,number,url)
 
-cp gh_release_notes_top gh_release_notes
+cp gh_release_notes_top.md gh_release_notes.md
 if [[ $json != "[]" ]]; then
 (
 	echo -n 'This build was created by [merging pull request '
@@ -16,11 +16,11 @@ if [[ $json != "[]" ]]; then
 	echo -n ')]('
 	echo -n $json | jq -j '.[0]|{url}|join(" ")'
 	echo ' )'
-) >> gh_release_notes
+) >> gh_release_notes.md
 else
 (
 	echo "This build was created by directly pushing to the Subsurface repo."
 	echo "The latest commit was [$(git log --pretty=format:"%an: '%s'" -n1)](https://github.com/subsurface/subsurface/commit/$1 )"
-) >> gh_release_notes
+) >> gh_release_notes.md
 fi
-cat gh_release_notes_bottom >> gh_release_notes
+cat gh_release_notes_bottom.md >> gh_release_notes.md