Support format html event attributes (#17909)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: fisker <lionkay@gmail.com>

changelog_unreleased/html/17909.md

@@ -0,0 +1,26 @@
+#### Format inline event handler (#17909 by @kovsu)
+
+<!-- prettier-ignore -->
+```html
+<!-- Input -->
+<button
+  type="button"
+  onclick="console .log(    'Hello, this is my old-fashioned event handler!')"
+>Press me</button>
+
+<!-- Prettier stable -->
+<button
+  type="button"
+  onclick="console .log(    'Hello, this is my old-fashioned event handler!')"
+>
+  Press me
+</button>
+
+<!-- Prettier main -->
+<button
+  type="button"
+  onclick="console.log('Hello, this is my old-fashioned event handler!')"
+>
+  Press me
+</button>
+```