Use actual nbsp character instead of HTML entity when avoiding wrapping rule names in rules list

[bmish]

Not a bug fix but more like a tweak with no user-facing behavior change.

Avoids excessively-long name column in markdown due to repeated   HTML entity as seen here: https://github.com/sindresorhus/eslint-plugin-unicorn/blob/7d804e3ce8ecb9d51b16d558eeae6dc12a81ec4c/readme.md?plain=1#L53

Non-breaking space character copied from here: https://unicode-table.com/en/00A0/

Idea suggested here: jsx-eslint/eslint-plugin-react#3469 (comment)

This is a follow-up to the original issue for avoiding wrapping rule names: #110.

The only downside I see is that it this non-breaking space can be indistinguishable from a regular space to many readers and could cause confusion. The HTML entity is more clear.

What do you think? Add thumbs up or thumbs down emoji to this PR.

CC: @ljharb @sindresorhus @fisker

[ljharb]

LGTM - it makes the raw markdown visually cleaner, and there's no user confusion issue since the doc generator will be creating it.