add docs for bool: (#874)

Co-authored-by: Sarah <[email protected]>

src/routes/reference/jsx-attributes/bool.mdx

@@ -0,0 +1,21 @@
+---
+title: bool:*
+---
+
+`bool:*` controls the presence of an attribute in an element.
+When the value is `truthy` it adds the `attribute` to the element.
+Alternatively, when the value is `falsy` it removes the `attribute` from the element.
+This attribute is most useful for Web Components.
+
+```tsx
+<my-element bool:status={prop.value} />
+```
+
+```tsx
+// Assuming `prop.value` is `truthy`, then it becomes
+<my-element status />
+
+// And when `falsy`, then it becomes
+<my-element />
+
+```

src/routes/reference/jsx-attributes/data.json

@@ -3,6 +3,7 @@
 	"pages": [
 		"attr.mdx",
 		"classlist.mdx",
+		"bool.mdx",
 		"innerhtml-or-textcontent.mdx",
 		"on_.mdx",
 		"on-and-oncapture.mdx",