Change ordered list order, lower-alpha before lower-roman

[zmanion]

I perhaps moved too quickly but also opened #3087.

Describe the bug

Change ordered list styles used in markdown in at least issues and wikis to use what seems like the more common and intuitive order: decimal, lower-alpha, lower-roman. This alternates numbers and letters and seems to follow more common convention, at least among U.lS. english styles. I looked at least briefly and couldn't find style guidance or use of the current order over the proposed new order.

I read and tried various ways to override the order just for my content, but this seems to be difficult if not impossible since GitHub blocks various style/CSS modifications (probably for legitimate security reasons).

Here are a semi-related issue and discussion.

To Reproduce

1. Dog (1.)
   1. German Shepherd (should be a.)
   1. Belgian Shepherd (b.)
      1. Malinois (i.)
      1. Groenendael (ii.)
      1. Tervuren (iii.)
1. Cat (2.)
   1. Siberian (a.)
   1. Siamese (b.)

1. Dog (1.)
   1. German Shepherd (should be a.)
   2. Belgian Shepherd (b.)
      1. Malinois (i.)
      2. Groenendael (ii.)
      3. Tervuren (iii.)
2. Cat (2.)
   1. Siberian (a.)
   2. Siamese (b.)

Expected behavior

Order should be decimal, lower-alpha, lower-roman.

Desktop (please complete the following information):

macOS, 148.0.7778.216 (arm64), 151.0.2 (aarch64)