refactor(issue,pr): trim help, restating comments and single-use helpers

Cut issue, pr, label, milestone and comment examples to at most three, drop
doc comments that only restate the name, fold the comment and attachment
argument lookups into one closure each, and inline label helpers with one
caller.

Signed-off-by: bircni <bircni@icloud.com>

internal/app/issue_edit.go

@@ -14,7 +14,6 @@ import (
 	"github.com/spf13/cobra"
 )
 
-// errNothingToEdit is the shared answer to edit commands without anything to change.
 var errNothingToEdit = clierr.Wrap(clierr.Usage, errors.New("nothing to edit; pass a flag such as --title (see --help)"))
 
 func (a *application) issueEditCommand() *cobra.Command {
@@ -25,16 +24,14 @@ func (a *application) issueEditCommand() *cobra.Command {
 starting from its current values. Label and assignee flags add to or remove from each issue's
 current values; the --set flags replace them.`, Example: `$ tea issue edit 12 --title "Crash on start" --add-label bug
 $ tea issue edit 12 13 --add-assignee @me --milestone v1.0
-$ tea issue edit 12 --remove-label wontfix --remove-milestone
-$ tea issue edit 12 --body-file notes.md`, Annotations: map[string]string{"tea.arguments": issueArguments}, Args: usageArgs(cobra.MinimumNArgs(1)), RunE: func(cmd *cobra.Command, args []string) (runErr error) {
+$ tea issue edit 12 --remove-label wontfix --remove-milestone`, Annotations: map[string]string{"tea.arguments": issueArguments}, Args: usageArgs(cobra.MinimumNArgs(1)), RunE: func(cmd *cobra.Command, args []string) (runErr error) {
 		var draft terminal.Draft
 		defer finishDraft(&draft, &runErr)
 		if err := validateBodySources(cmd); err != nil {
 			return err
 		}
-		prompt := a.canPrompt()
 		if !localFlagsChanged(cmd) {
-			if !prompt || a.deps.IssueEditForm == nil {
+			if !a.canPrompt() || a.deps.IssueEditForm == nil {
 				return errNothingToEdit
 			}
 			target, numbers, err := a.resolveRefs(cmd, args, issueRef)
@@ -128,7 +125,6 @@ $ tea issue edit 12 --body-file notes.md`, Annotations: map[string]string{"tea.a
 	return cmd
 }
 
-// editedIssue words the done line of an issue edit.
 func editedIssue(t target) func(services.Issue) string {
 	return func(item services.Issue) string {
 		return "Edited " + discussionNoun(item.Kind) + " " + refLabel(t.Repo, item.Number, item.Title)