Upgraded to Web Add-on manifest version 3. This comes with a security feature which can also be helpful outside of adding extra security. This add-on will now not work on any site unless you click on the add-on's icon to allow it to work once, or you can follow these steps to allow it to always work automatically on a site: Click on the extensions puzzle piece icon in the top right, then on the gear next to this add-on's icon. Finally, select "Always allow on <the site you are on will appear here>". Alternately, if you want to disable it for a site, do the same steps except on the last step choose "Only when clicked" instead.
Also, when saving rules, you can see when the rules were last saved.

Making a new version so the file in the Firefox addon store is in sync with the repo. The only change is the shortening of the description in the manifest and the addition of a 128x128 pixel icon for Chrome, that won't be used in Firefox.

No working changes in this version, just restructuring the folders. Don't forget to check rules/recommendedRules.json though for the tumblr video volume bar rule if you don't have that yet.

Enabled the addon to run on iframes. This was needed to create a rule that could add volume bars to Tumblr videos, which has been included in the recommendedRules.json.