guess release notes: special-case Perl

We would like to show useful links in the release notes for new Perl
versions, just like we did before we switched from using `please.sh
upgrade perl` to branch deployments. See also
git-for-windows/MSYS2-packages#97 (comment)

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

GitForWindowsHelper/component-updates.js

@@ -66,6 +66,8 @@ const guessReleaseNotes = async (context, issue) => {
     }
 
     const matchURL = async () => {
+        if (package_name === 'perl') return `http://search.cpan.org/dist/perl-${version}/pod/perldelta.pod`
+
         if (!issue.pull_request) return matchURLInIssue(issue)
 
         const match = issue.body.match(/See (https:\/\/\S+) for details/)

__tests__/component-updates.test.js

@@ -77,4 +77,13 @@ http://www.gnutls.org/news.html#2023-02-10`
         type: 'feature',
         message: 'Comes with [GNU TLS v3.8.0](https://lists.gnupg.org/pipermail/gnutls-help/2023-February/004816.html).'
     })
+
+    expect(await guessReleaseNotes(context, {
+        labels: [{ name: 'component-update' }],
+        title: '[New perl version] v5.36.1',
+        body: `\nhttps://github.com/Perl/perl5/releases/tag/v5.36.1`
+    })).toEqual({
+        type: 'feature',
+        message: 'Comes with [Perl v5.36.1](http://search.cpan.org/dist/perl-5.36.1/pod/perldelta.pod).'
+    })
 })