html: Do not export Node in the public API

It is not usable on its own and it is
not in the output of any public method.

crates/ruma-html/CHANGELOG.md

@@ -1,5 +1,10 @@
 # [unreleased]
 
+Breaking Changes:
+
+- Do not export `Node` in the public API, it is not usable on its own and it is
+  not in the output of any public method.
+
 Improvements:
 
 - Add support for deprecated HTML tags, according to Matrix 1.10

crates/ruma-html/src/html.rs

@@ -297,7 +297,7 @@ impl fmt::Display for Html {
 /// An HTML node.
 #[derive(Debug)]
 #[non_exhaustive]
-pub struct Node {
+pub(crate) struct Node {
     pub(crate) parent: Option<usize>,
     pub(crate) prev_sibling: Option<usize>,
     pub(crate) next_sibling: Option<usize>,
@@ -320,7 +320,7 @@ impl Node {
     }
 
     /// Returns the data of this `Node` if it is an Element (aka an HTML tag).
-    pub fn as_element(&self) -> Option<&ElementData> {
+    pub(crate) fn as_element(&self) -> Option<&ElementData> {
         as_variant!(&self.data, NodeData::Element)
     }
 

crates/ruma-html/src/lib.rs

@@ -16,6 +16,6 @@ mod sanitizer_config;
 
 pub use self::{
     helpers::*,
-    html::{ElementData, Html, Node},
+    html::{ElementData, Html},
     sanitizer_config::SanitizerConfig,
 };