Type: Optical Margin Alignment hangs punctuation in right-to-left paragraphs

Optical Margin Alignment and Roman Hanging Punctuation left every
right-to-left paragraph of point and area type, and type on a path
whose first paragraph runs right to left, as it was: the quotation
marks, full stops and commas at the ends of its lines stayed inside
the margins.

A right-to-left line now hangs at the margins its alignment places it
against, as a left-to-right line does. Auto aligns a right-to-left
line at its right, so it hangs there. The line is read from right to
left: where it hangs at its left margin, a full stop and the quotation
mark after it that end the line hang together. In vertical type,
where the characters of a right-to-left paragraph run from the top
down, the pair is read from the top.

Type on a path whose first paragraph runs right to left hangs at its
brackets by the same rule. In horizontal type, Auto places it at the
end bracket, so it hangs there. On a closed path, its hang at the end
bracket gets the space between the end and start brackets before its
hang at the start bracket does, as in right-aligned type.

A justified right-to-left line of one word is spread between its
letters as they are drawn. The gap after each letter went to the
letter that follows it in the text, so the two leftmost letters
touched and the word ended one gap short of the right margin.

Docs: docs/mcp.md, docs/type-parity.md, docs/target-app-parity.md.

crates/doc/src/text.rs

@@ -1329,9 +1329,8 @@ pub struct TextObject {
     pub wrap: Vec<WrapShape>,
     /// Type › Optical Margin Alignment: in every paragraph, Latin punctuation and the slanted
     /// sides of letters such as A and W at a line's start or end hang outside the margin there
-    /// (point and area type of left-to-right paragraphs, and left-to-right type on a path at its
-    /// brackets; see the layout's `optical_hangs`). Off for new type and for documents from before
-    /// it, and saved only when on.
+    /// (point and area type, and type on a path at its brackets; see the layout's `optical_hangs`).
+    /// Off for new type and for documents from before it, and saved only when on.
     #[serde(default, rename = "opticalMarginAlignment", skip_serializing_if = "crate::skip::is_default")]
     pub optical_margin: bool,
     /// Cached layout bounds in text space, filled in by the layout engine (not serialized).