Add documentation about `%n` and `%%` tokens for `--format`

commands/issue.go

@@ -105,6 +105,10 @@ With no arguments, show a list of open issues.
 
 		%uI: updated date, ISO 8601 format
 
+		%n: newline
+
+		%%: a literal %
+
 	-m, --message=<MESSAGE>
 		The text up to the first blank line in <MESSAGE> is treated as the issue
 		title, and the rest is used as issue description in Markdown format.

commands/pr.go

@@ -113,6 +113,10 @@ pr checkout <PR-NUMBER> [<BRANCH>]
 
 		%mI: merged date, ISO 8601 format
 
+		%n: newline
+
+		%%: a literal %
+
 	-o, --sort=<SORT_KEY>
 		Sort displayed issues by "created" (default), "updated", "popularity", or "long-running".
 

commands/release.go

@@ -136,6 +136,10 @@ With '--exclude-prereleases', exclude non-stable releases from the listing.
 
 		%pI: published date, ISO 8601 format
 
+		%n: newline
+
+		%%: a literal %
+
 	<TAG>
 		The git tag name for this release.