PS4/PS5 Firmware Series Convention

Convention used by this repo to refer to a set of firmwares.

The pattern X.Yx means X.Y0 <= firmware < (X + 1).V0. Y is either 0 or 5. V is
5 if Y is 0, 0 if Y is 5.

examples:
* 6.0x refer to 6.00 <= fw < 6.50.
* 6.5x refer to 6.50 <= fw < 7.00.

The pattern X.xx means X.00 <= firmware < (X + 1).00.

examples:
* 6.xx refer to 6.00 <= fw < 7.00.
* 7.xx refer to 7.00 <= fw < 8.00.