docs: add mpv.launchMode to config docs, add changelog:docs generator, format

- Document the new mpv.launchMode option in the configuration docs page
- Add changelog:docs command to auto-generate docs-site/changelog.md from root CHANGELOG.md
- Add breaking changes support to the changelog fragment generator
- Fix docs-sync test to only compare current minor release headings
- Apply prettier formatting to source files

launcher/mpv.ts

@@ -264,10 +264,7 @@ function getLinuxDesktopEnv(env: NodeJS.ProcessEnv): LinuxDesktopEnv {
   };
 }
 
-function shouldForceX11MpvBackend(
-  args: Pick<Args, 'backend'>,
-  env: NodeJS.ProcessEnv,
-): boolean {
+function shouldForceX11MpvBackend(args: Pick<Args, 'backend'>, env: NodeJS.ProcessEnv): boolean {
   if (process.platform !== 'linux' || !env.DISPLAY?.trim()) {
     return false;
   }