Use the same format as GitHub's default for the release notes

We're changing the format for the auto-generated release notes from:

- This is the PR title #1 (@author)

to:

* This is the PR title by @author in solidusio#1

By mimicking the default GitHub format, we make it easier to generate
them manually through GitHub's "Generate release notes" [1] button or
through the API [2].

At the same time, we're fixing the missing links to the PR when we copy
the draft content to the Changelog file, as GitHub doesn't autolink
references in files. From their documentation [3]:

> Note: Autolinked references are not created in wikis or files in a repository.

We'll still miss the link to the contributor, but it's a tradeoff we pay
to make our lives easier if the automation fails. Anyway, it can be
accessed once landed on the pull request URL.

[1] - https://docs.github.com/en/repositories/releasing-projects-on-github/automatically-generated-release-notes
[2] - https://docs.github.com/en/rest/releases/releases?apiVersion=2022-11-28#generate-release-notes-content-for-a-release
[3] - https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/autolinked-references-and-url

Closes solidusio#4904 & 4908

dev_tools/lib/solidus/release_drafter.rb

@@ -37,7 +37,13 @@ def call(pr_number:, current_diff_source_tag:, candidate_tag:, branch:)
       return if pr_labels.include?(SKIP_LABEL) || matching_labels.empty?
 
       draft = @client.fetch_draft(tag: candidate_tag)
-      Builder.new(draft: draft, categories: LABELS.values, prepend: NO_EDIT_WARNING, append: full_changelog(current_diff_source_tag, candidate_tag))
+      Builder.new(
+        draft: draft,
+        categories: LABELS.values,
+        prepend: NO_EDIT_WARNING,
+        append: full_changelog(current_diff_source_tag, candidate_tag),
+        number_link_builder: number_link_builder
+      )
         .then { |builder| add_pr(builder, pr, matching_labels) }
         .then { |draft| save_release(draft, candidate_tag, branch) }
     end
@@ -68,5 +74,9 @@ def full_changelog(current_diff_source_tag, candidate_tag)
         **Full Changelog**: https://github.com/#{@repository}/compare/#{current_diff_source_tag}...#{candidate_tag}
       TXT
     end
+
+    def number_link_builder
+      ->(number) { "https://github.com/#{@repository}/pull/#{number}" }
+    end
   end
 end

dev_tools/lib/solidus/release_drafter/builder.rb

@@ -18,15 +18,16 @@ class Builder
 
       TITLE_SEPARATOR = SEPARATOR
 
-      ENTRY_TEMPLATE = lambda do |title, number, user|
-        "- #{title} ##{number} (@#{user})"
+      ENTRY_TEMPLATE = lambda do |title, link, user|
+        "* #{title} by @#{user} in #{link}"
       end.freeze
 
       ENTRY_SEPARATOR = SEPARATOR
 
       SECTION_SEPARATOR = SEPARATOR + SEPARATOR
 
-      def initialize(draft:, categories:, prepend: '', append: '')
+      def initialize(draft:, categories:, number_link_builder:, prepend: '', append: '')
+        @number_link_builder = number_link_builder
         @categories = Set[*categories]
         @prepend = prepend
         @prepend_pattern = /^#{Regexp.quote(@prepend)}/m
@@ -39,7 +40,7 @@ def initialize(draft:, categories:, prepend: '', append: '')
       end
 
       def add(title:, number:, user:, categories:)
-        ENTRY_TEMPLATE.(title, number, user)
+        ENTRY_TEMPLATE.(title, @number_link_builder.(number), user)
           .then { |entry| add_to_ast(entry, categories) }
           .then { |ast| @draft.with(content: unparse(ast)) }
       end