[FEATURE REQUEST] Add Swedish translation

[hfrizen]

Describe the bug
There is no Swedish translation of the add-on.

To Reproduce
N/A (there is no Swedish language file)

Expected behavior
The add-on should be translated.

Screenshots
N/A

Desktop (please complete the following information):

1. Os: Debian GNU/Linux 12.8, KDE Plasma 5.27.5
2. Thunderbird version: 128.5.0esr(64-bits)
3. Extension version: 5.8.2
4. Image details - format, size: N/A
5. Extension settings: Default
6. If you are having issues with manual resizing: N/A

• Is the notification displayed when image is attached
• Is the notification displayed when image is inserted inline
• Is there an option to resize the image when right clicking on attached / inline images

7. Did this feature work in previous versions: This is my first installation.
8. Have you tried updating the addon to the latest version by downloading latest release: I have only tried 5.8.2 which is the latest version.

Additional context
N/A

[hfrizen]

Here is a first version, I will use it on my computer for awhile, I guess I will find some issues with the translation.
messages.json

Message to the Swedish users: Om du vill prova översättningen är det bara att öppna tilläggets xpi-fil i valfritt arkivprogram och lägga till ovanstående fil i mappen _locales/sv/ och därefter installera (eller ominstallera) tillägget.
Hör gärna av dig om du har några synpunkter!

How to proceed when I consider it to be ready in a week or so?

[memeller]

Please create a pull request, if you would like to contribute.

[hfrizen]

Thanks for your reply, I will do in the coming weeks!