Fix various typos

Found via `codespell -q 3 -S *.ts,./src/libraries,./webpage/src/??/*,./webpage/yarn.lock,./appveyor/OpenSSL/LICENSE  -L ro,ser`

docs/scripting/examples/callback.qml

@@ -2,7 +2,7 @@ import QtQml 2.0
 import QOwnNotesTypes 1.0
 
 /**
- * This script is a short example of how to use detatched processes and callbacks
+ * This script is a short example of how to use detached processes and callbacks
  * to relieve the UI thread.
  * Visit http://docs.qownnotes.org/ for more information about scripting
  */

docs/scripting/examples/note-text-from-5pm-mail.qml

@@ -62,7 +62,7 @@ QtObject {
         // add the headline of the task
         var text = headline + "\n";
         
-        // add "=" charactes so that the headline is really a headline
+        // add "=" characters so that the headline is really a headline
         for (var i = 0; i < headline.length; i++) {
             text += "=";
         }