Docs: Add docs for actionview-no-void-element-content rule

Author: marcoroth

javascript/packages/linter/docs/rules/README.md

@@ -6,6 +6,7 @@ This page contains documentation for all Herb Linter rules.
 
 - [`actionview-no-silent-helper`](./actionview-no-silent-helper.md) - Disallow silent ERB tags for Action View helpers
 - [`actionview-no-silent-render`](./actionview-no-silent-render.md) - Disallow calling `render` without outputting the result
+- [`actionview-no-void-element-content`](./actionview-no-void-element-content.md) - Disallow content arguments for void Action View elements
 - [`erb-comment-syntax`](./erb-comment-syntax.md) - Disallow Ruby comments immediately after ERB tags
 - [`erb-no-case-node-children`](./erb-no-case-node-children.md) - Don't use `children` for `case/when` and `case/in` nodes
 - [`erb-no-conditional-html-element`](./erb-no-conditional-html-element.md) - Disallow conditional HTML elements

javascript/packages/linter/docs/rules/actionview-no-void-element-content.md

@@ -0,0 +1,57 @@
+# Linter Rule: Disallow content arguments for void Action View elements
+
+**Rule:** `actionview-no-void-element-content`
+
+## Description
+
+Void HTML elements like `img`, `br`, and `hr` cannot have content. When using Action View helpers like `tag.img` or `content_tag :img`, passing a positional content argument will raise a runtime error in Rails.
+
+## Rationale
+
+In Rails, `tag.*` helpers for void elements do not accept positional arguments for content. Calling `tag.img "/image.png"` raises `wrong number of arguments (given 1, expected 0)` at runtime.
+
+The correct way to set attributes on void elements is to use keyword arguments, such as `tag.img src: "/image.png"`. This rule catches the error at lint time before it reaches production.
+
+## Examples
+
+### Good
+
+```erb
+<%= tag.img src: "/image.png", alt: "Photo" %>
+```
+
+```erb
+<%= tag.br %>
+```
+
+```erb
+<%= tag.hr class: "divider" %>
+```
+
+```erb
+<%= content_tag :img, src: "/image.png", alt: "Photo" %>
+```
+
+### Bad
+
+```erb
+<%= tag.img "/image.png" %>
+```
+
+```erb
+<%= tag.br "hello" %>
+```
+
+```erb
+<%= content_tag :img, "hello" %>
+```
+
+```erb
+<%= content_tag :br, "hello" %>
+```
+
+## References
+
+* [Rails `ActionView::Helpers::TagHelper#tag`](https://api.rubyonrails.org/classes/ActionView/Helpers/TagHelper.html#method-i-tag)
+* [Rails `ActionView::Helpers::TagHelper#content_tag`](https://api.rubyonrails.org/classes/ActionView/Helpers/TagHelper.html#method-i-content_tag)
+* [HTML Void Elements](https://html.spec.whatwg.org/multipage/syntax.html#void-elements)