[editor] Slightly shorten the en-US freetext_default_content placeholder text

Now that it's possible to change the font-size, this placeholder string feels a little bit long (especially for larger font-sizes).

Given that Editing is not enabled/released yet, I hope that it should be fine to update this without changing the l10n-id.

Author: Snuffleupagus

l10n/en-US/viewer.properties

@@ -258,7 +258,7 @@ editor_free_text_label=FreeText Annotation
 editor_ink.title=Add Ink Annotation
 editor_ink_label=Ink Annotation
 
-freetext_default_content=Enter some text…
+freetext_default_content=Enter text…
 
 # Editor Parameters
 editor_free_text_font_color=Font Color

web/l10n_utils.js

@@ -82,7 +82,7 @@ const DEFAULT_L10N_STRINGS = {
   web_fonts_disabled:
     "Web fonts are disabled: unable to use embedded PDF fonts.",
 
-  freetext_default_content: "Enter some text…",
+  freetext_default_content: "Enter text…",
 };
 
 function getL10nFallback(key, args) {