Crash when clicking the help icon in advanced search

[ricardograca]

Whenever I click on the help icon (?) in advanced search the app crashes. Since I have no idea how advanced search works I was looking to get some help after typing in the !, but the app just crashes.

Steps to reproduce

1. Open Tagger
2. Open a music folder
3. Type ! in the search input
4. Click the question mark icon

Expected results

Some sort of help window pops up.

Actual results

The app crashes.

Stack trace

UnhandledException - unhandled exception: System.ArgumentNullException: Value cannot be null. (Parameter 'stream')
   at System.IO.StreamReader..ctor(Stream stream, Encoding encoding, Boolean detectEncodingFromByteOrderMarks, Int32 bufferSize, Boolean leaveOpen)
   at NickvisionTagger.Shared.Helpers.DocumentationHelpers.GetHelpURL(String pageName) in /build/tagger/parts/tagger/src/NickvisionTagger.Shared/Helpers/DocumentationHelpers.cs:line 30
   at NickvisionTagger.GNOME.Views.MainWindow.AdvancedSearchInfo(Button sender, EventArgs e) in /build/tagger/parts/tagger/src/NickvisionTagger.GNOME/Views/MainWindow.cs:line 1711
   at GObject.Signal`1.<>c__DisplayClass11_0.<Connect>b__0(Value returnValue, Value[] parameters)
   at GObject.Closure.InternalCallback(IntPtr closure, IntPtr returnValuePtr, UInt32 nParamValues, IntPtr paramValuesData, IntPtr invocationHint, IntPtr userData)

System info

• Ubuntu 22.04.4 x86_64.
• Kernel 6.5.0-44-generic.
• tagger-debug.txt