implement email editor w/ live(?) preview

not accessible in the ui currently, but the object is available as
window.ee for testing.

lang/admin/en-us.json

@@ -33,6 +33,8 @@
         "announce": "Announce",
         "subject": "Email Subject",
         "message": "Message",
+        "variables": "Variables",
+        "preview": "Preview",
         "markdownSupported": "Markdown is supported.",
         "modifySettings": "Modify Settings",
         "modifySettingsDescription": "Apply settings from an existing profile, or source them directly from a user.",
@@ -76,6 +78,7 @@
         "userCreated": "User {n} created.",
         "createProfile": "Created profile {n}.",
         "saveSettings": "Settings were saved",
+        "saveEmail": "Email saved.",
         "sentAnnouncement": "Announcement sent.",
         "setOmbiDefaults": "Stored ombi defaults.",
         "errorConnection": "Couldn't connect to jfa-go.",
@@ -85,6 +88,7 @@
         "errorSettingsFailed": "Application failed.",
         "errorLoginBlank": "The username and/or password were left blank.",
         "errorUnknown": "Unknown error.",
+        "errorSaveEmail": "Failed to save email.",
         "errorBlankFields": "Fields were left blank",
         "errorDeleteProfile": "Failed to delete profile {n}",
         "errorLoadProfiles": "Failed to load profiles.",