[RTL] Footer icon-group placement and spacing issues

[chalin]

In an RTL page:

• The left-side icon group isn't left-aligned
• The spacing between icons in the right-side icon group is a bit off for the last icon

... as illustrated in the following screenshot:

[chalin]

Another example: from https://example.docsy.dev/fa/docs/. Note the spacing and location of the footer icons:

[chalin]

Fixed via:

• RTL support via a single main style file #2093

As confirmed via:

• Upgrade Docsy to v0.10.0-33-gfe0d785, add rtlcss pkg docsy-example#322