Add support for the "selfClosing" dialect. (#3)

Upgrade @lezer/html to 1.1.0 and add support for the newly introduced
"selfClosing" dialect.

FEATURE: Add a `selfClosingTags` option to `html` that enables `/>` syntax.

package.json

@@ -31,7 +31,7 @@
     "@codemirror/lang-javascript": "^6.0.0",
     "@codemirror/language": "^6.0.0",
     "@codemirror/state": "^6.0.0",
-    "@lezer/html": "^1.0.1",
+    "@lezer/html": "^1.1.0",
     "@lezer/common": "^1.0.0",
     "@codemirror/view": "^6.2.2"
   },

src/html.ts

@@ -84,6 +84,10 @@ export function html(config: {
   /// expect to only be parsing a fragment of HTML text, not a full
   /// document).
   matchClosingTags?: boolean,
+  // By default, the parser does not allow arbitrary self-closing tags.
+  // Set this to `true` to turn on support for `/>` self-closing tag
+  // syntax.
+  selfClosingTags?: boolean,
   /// Determines whether [`autoCloseTags`](#lang-html.autoCloseTags)
   /// is included in the support extensions. Defaults to true.
   autoCloseTags?: boolean,
@@ -94,6 +98,7 @@ export function html(config: {
 } = {}) {
   let lang = htmlLanguage
   if (config.matchClosingTags === false) lang = lang.configure({dialect: "noMatch"})
+  if (config.selfClosingTags === true) lang = lang.configure({dialect: "selfClosing"})
   return new LanguageSupport(lang, [
     htmlLanguage.data.of({autocomplete: htmlCompletionSourceWith(config)}),
     config.autoCloseTags !== false ? autoCloseTags: [],