Add ordinal ª and º indicators

[sdalmonte]

This pull request adds the ordinal indicators ª and º.

character	Unicode value	symbol
ª	U+00AA FEMININE ORDINAL INDICATOR	ordinal.a
º	U+00BA MASCULINE ORDINAL INDICATOR	ordinal.o

[MDLC01]

For reference, those characters are documented in the Unicode Core Specification.¹ Notably, they do not seem to be included for compatibility reasons, which motivates their addition to Codex.

Footnotes

1. https://www.unicode.org/versions/Unicode17.0.0/core-spec/chapter-7/#G6207 ↩

[MDLC01]

You will also need to update the changelog in CHANGELOG.md