Clarify hydration instructions.

There should not be any spacing within the root dom. If there is, React will
fail to hydrate. We also remove an incorrect comment on `edit.html.erb` and
refer back to the docs for instructions.

docs/recipes/server-side-rendering.md

@@ -96,20 +96,15 @@ Add a line to your `package.json` like so:
 +    "build:ssr": "node ./build-ssr.mjs"
 ```
 
-Replace `<div id="app">` in your ERB templates with:
+Replace `<div id="app"></div>` in your ERB templates `index.html.erb` with:
 
 ```erb
-<% initial_state = controller.render_to_string(@virtual_path ,formats: [:json], locals: local_assigns, layout: true) %>
-
-<script type="text/javascript">
-  window.SUPERGLUE_INITIAL_PAGE_STATE=<%= initial_state.html_safe %>;
-</script>
-
-<div id="app">
-  <%= Humid.render(initial_state).html_safe %>
-</div>
+<div id="app"><%= Humid.render(initial_state).html_safe %></div>
 ```
 
+!> Do not render spacing above. If you do, React will not hydrate properly and
+warn `Hydration failed because the initial UI does not match what was rendered on the server`
+
 In `application.js` change this:
 
 ```

superglue_rails/lib/generators/rails/templates/web/edit.html.erb

@@ -4,9 +4,7 @@
   window.SUPERGLUE_INITIAL_PAGE_STATE=<%%= initial_state.html_safe %>;
 </script>
 
-<div id="app">
-  <%%# If you need SSR follow instructions at %>
-  <%%# https://github.com/thoughtbot/superglue/blob/main/docs/recipes/server-side-rendering.md %>
-  <%%# and uncomment the following line %>
-  <%%#= Humid.render(initial_state).html_safe %>
-</div>
+<%%# If you need SSR follow instructions at %>
+<%%# https://github.com/thoughtbot/superglue/blob/main/docs/recipes/server-side-rendering.md %>
+<div id="app"></div>
+

superglue_rails/lib/generators/rails/templates/web/index.html.erb

@@ -4,4 +4,6 @@
   window.SUPERGLUE_INITIAL_PAGE_STATE=<%%= initial_state.html_safe %>;
 </script>
 
+<%%# If you need SSR follow instructions at %>
+<%%# https://github.com/thoughtbot/superglue/blob/main/docs/recipes/server-side-rendering.md %>
 <div id="app"></div>

superglue_rails/lib/generators/rails/templates/web/new.html.erb

@@ -4,4 +4,6 @@
   window.SUPERGLUE_INITIAL_PAGE_STATE=<%%= initial_state.html_safe %>;
 </script>
 
+<%%# If you need SSR follow instructions at %>
+<%%# https://github.com/thoughtbot/superglue/blob/main/docs/recipes/server-side-rendering.md %>
 <div id="app"></div>

superglue_rails/lib/generators/rails/templates/web/show.html.erb

@@ -4,4 +4,6 @@
   window.SUPERGLUE_INITIAL_PAGE_STATE=<%%= initial_state.html_safe %>;
 </script>
 
+<%%# If you need SSR follow instructions at %>
+<%%# https://github.com/thoughtbot/superglue/blob/main/docs/recipes/server-side-rendering.md %>
 <div id="app"></div>