Add pull request manually merge instruction (#13840)

* add pull request command line instructions

* Add pull request manually merge instuction

* Fix styles

* Fix lint

* Move inline style to class file

* add space between merge button and hint text

* Add sentence end charcter

* Change the language file

* adjust secondary bg

* further adjustment

Co-authored-by: silverwind <me@silverwind.io>

options/locale/locale_en-US.ini

@@ -86,6 +86,9 @@ write = Write
 preview = Preview
 loading = Loading…
 
+step1 = Step 1:
+step2 = Step 2:
+
 error404 = The page you are trying to reach either <strong>does not exist</strong> or <strong>you are not authorized</strong> to view it.
 
 [error]
@@ -1296,6 +1299,10 @@ pulls.update_not_allowed = You are not allowed to update branch
 pulls.outdated_with_base_branch = This branch is out-of-date with the base branch
 pulls.closed_at = `closed this pull request <a id="%[1]s" href="#%[1]s">%[2]s</a>`
 pulls.reopened_at = `reopened this pull request <a id="%[1]s" href="#%[1]s">%[2]s</a>`
+pulls.merge_instruction_hint = `You can also view <a class="show-instruction">command line instructions</a>.`
+
+pulls.merge_instruction_step1_desc = From your project repository, check out a new branch and test the changes.
+pulls.merge_instruction_step2_desc = Merge the changes and update on Gitea.
 
 milestones.new = New Milestone
 milestones.open_tab = %d Open