Need a way to fix the initial size of the Todo panel

[heewonlee-nj]

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a feature request that matches the one I want to file, without success.

Problem Description

I'm currently using Todoist a todo service, and the initial width of todo panel is too small, so I have to resize it every time I reload Ferdium.
It would be great if there was a way to fix the size of the Todo panel.

Proposed Solution

Keep the size of the Todo panel resized by the user even after Ferdium restarts and reloads.

Alternatives Considered

While a little less UX-friendly, there is also a way to allow the size of the initial Todo panel to be set in the appearance settings.

Additional Information

This feature was mentioned in #1120 (comment), but there doesn't appear to be any follow-up discussion, so we're creating a separate issue.

[RaphaelJenni]

I created a pull request for this.

(Team effort at #Hackergarten)