Upstream xoofx/markdig state of the touched files before 27b8c9eb56

site/docs/extensions/emphasis-extras.md

@@ -0,0 +1,93 @@
+---
+title: Emphasis extras
+---
+
+# Emphasis extras
+
+Enable with `.UseEmphasisExtras()` (included in `UseAdvancedExtensions()`).
+
+This extension adds several emphasis styles beyond standard bold and italic.
+
+If you need improved emphasis parsing for Chinese/Japanese/Korean (CJK) text, see [CJK friendly emphasis](cjk-friendly-emphasis.md).
+
+## Strikethrough
+
+Wrap text with `~~` for strikethrough:
+
+```markdown
+This is ~~deleted~~ text.
+```
+
+This is ~~deleted~~ text.
+
+## Subscript
+
+Wrap text with `~` for subscript:
+
+```markdown
+H~2~O is water.
+```
+
+H~2~O is water.
+
+## Superscript
+
+Wrap text with `^` for superscript:
+
+```markdown
+2^10^ is 1024.
+```
+
+2^10^ is 1024.
+
+## Inserted text
+
+Wrap text with `++` for inserted/underlined text:
+
+```markdown
+This text has been ++inserted++.
+```
+
+This text has been ++inserted++.
+
+## Marked/highlighted text
+
+Wrap text with `==` for marked/highlighted text:
+
+```markdown
+This is ==highlighted== text.
+```
+
+This is ==highlighted== text.
+
+## HTML output
+
+{.table}
+| Syntax | HTML output |
+|---|---|
+| `~~text~~` | `<del>text</del>` |
+| `~text~` | `<sub>text</sub>` |
+| `^text^` | `<sup>text</sup>` |
+| `++text++` | `<ins>text</ins>` |
+| `==text==` | `<mark>text</mark>` |
+
+## Selective activation
+
+By default, all emphasis extras are enabled. Use `EmphasisExtraOptions` to enable only specific ones:
+
+```csharp
+using Markdig.Extensions.EmphasisExtras;
+
+var pipeline = new MarkdownPipelineBuilder()
+    .UseEmphasisExtras(EmphasisExtraOptions.Strikethrough | EmphasisExtraOptions.Superscript)
+    .Build();
+```
+
+Available options:
+
+- `EmphasisExtraOptions.Strikethrough`
+- `EmphasisExtraOptions.Subscript`
+- `EmphasisExtraOptions.Superscript`
+- `EmphasisExtraOptions.Inserted`
+- `EmphasisExtraOptions.Marked`
+- `EmphasisExtraOptions.Default` (all of the above)