It's because you included all the referrer tracking info. If you just post the url it's less likely to do that. 500 pcs LED kit See the difference in the url?

BTW Adafruit is coming out with a brand new Prop-Maker RP2040 this week. ;)

As for the battery, because you're using a feather, there's a place for a lipo battery.

Please be aware that if you attempt to use Amazon lipo's those have backwards wiring and can fry your feather. There's a warning about it in the learn guide for every feather and it's definitely a real thing. For best compatibility and to ensure you get a battery that will definitely work without worry choose from one of these (except the coin cell).

The battery packs (18650's) have a lot of power but are heavy. The single cell dichromatic batteries are light weight and come in a variety of sizes. Since this is for a prop you should check the dimensions of the batteries vs the space you can allocate for the battery in your prop.

As for capacity. A coin cell battery has about a 220ma rating. A doubleA (AA) battery has about a 2800mah rating. 6 LED's will take about 120ma to run for 1 hour plus the draw for the feather itself. If you can go with the 2000mah battery I think you'll be happy with how long it'll drive your 6 LED's and feather.

All Adafruit Feather's have pass-through charging. Simply connect the battery to the battery port, plug the feather via USB, and it will automatically recharge the battery. Pass-through charging means you can use the feather while it's also charging the battery, excellent for fast coding iterations.