Add placeholder to keystring field

ssh/forms.py

@@ -5,7 +5,9 @@ from django.core.exceptions import ValidationError
 
 class KeyStringField(forms.CharField):
     def __init__(self, *args, **kwds):
-        kwds["widget"] = forms.Textarea
+        kwds["widget"] = forms.Textarea(attrs={
+            'placeholder': "ssh-key-type BASE64ENCODEDKEY hostname"
+        })
         super().__init__(*args, **kwds)
 
     def to_python(self, value):