Add a render image hook (#39768)

Images are now lazyloaded, they have width and height attributes and the classes are centralized.

Only applies to Markdown images

site/content/docs/5.3/getting-started/parcel.md

@@ -111,7 +111,7 @@ With dependencies installed and our project folder ready for us to start coding,
    npm start
    ```
 
-   <img class="img-fluid" src="/docs/{{< param docs_version >}}/assets/img/guides/parcel-dev-server.png" alt="Parcel dev server running">
+   ![Parcel dev server running](/assets/img/guides/parcel-dev-server.png)
 
 In the next and final section to this guide, we'll import all of Bootstrap's CSS and JavaScript.
 
@@ -150,7 +150,7 @@ Importing Bootstrap into Parcel requires two imports, one into our `styles.scss`
 
 3. **And you're done! 🎉** With Bootstrap's source Sass and JS fully loaded, your local development server should now look like this:
 
-   <img class="img-fluid" src="/docs/{{< param docs_version >}}/assets/img/guides/parcel-dev-server-bootstrap.png" alt="Parcel dev server running with Bootstrap">
+   ![Parcel dev server running with Bootstrap](/assets/img/guides/parcel-dev-server-bootstrap.png)
 
    Now you can start adding any Bootstrap components you want to use. Be sure to [check out the complete Parcel example project](https://github.com/twbs/examples/tree/main/parcel) for how to include additional custom Sass and optimize your build by importing only the parts of Bootstrap's CSS and JS that you need.
 

site/content/docs/5.3/getting-started/vite.md

@@ -135,7 +135,7 @@ With dependencies installed and our project folder ready for us to start coding,
    npm start
    ```
 
-   <img class="img-fluid" src="/docs/{{< param docs_version >}}/assets/img/guides/vite-dev-server.png" alt="Vite dev server running">
+   ![Vite dev server running](/assets/img/guides/vite-dev-server.png)
 
 In the next and final section to this guide, we’ll import all of Bootstrap’s CSS and JavaScript.
 
@@ -175,7 +175,7 @@ In the next and final section to this guide, we’ll import all of Bootstrap’s
 
 3. **And you're done! 🎉** With Bootstrap's source Sass and JS fully loaded, your local development server should now look like this:
 
-   <img class="img-fluid" src="/docs/{{< param docs_version >}}/assets/img/guides/vite-dev-server-bootstrap.png" alt="Vite dev server running with Bootstrap">
+   ![Vite dev server running with Bootstrap](/assets/img/guides/vite-dev-server-bootstrap.png)
 
    Now you can start adding any Bootstrap components you want to use. Be sure to [check out the complete Vite example project](https://github.com/twbs/examples/tree/main/vite) for how to include additional custom Sass and optimize your build by importing only the parts of Bootstrap's CSS and JS that you need.
 

site/content/docs/5.3/getting-started/webpack.md

@@ -141,7 +141,7 @@ With dependencies installed and our project folder ready for us to start coding,
    npm start
    ```
 
-   <img class="img-fluid" src="/docs/{{< param docs_version >}}/assets/img/guides/webpack-dev-server.png" alt="Webpack dev server running">
+   ![Webpack dev server running](/assets/img/guides/webpack-dev-server.png)
 
 In the next and final section to this guide, we'll set up the Webpack loaders and import all of Bootstrap's CSS and JavaScript.
 
@@ -244,7 +244,7 @@ Importing Bootstrap into Webpack requires the loaders we installed in the first
 
 4. **And you're done! 🎉** With Bootstrap's source Sass and JS fully loaded, your local development server should now look like this:
 
-   <img class="img-fluid" src="/docs/{{< param docs_version >}}/assets/img/guides/webpack-dev-server-bootstrap.png" alt="Webpack dev server running with Bootstrap">
+   ![Webpack dev server running with Bootstrap](/assets/img/guides/webpack-dev-server-bootstrap.png)
 
    Now you can start adding any Bootstrap components you want to use. Be sure to [check out the complete Webpack example project](https://github.com/twbs/examples/tree/main/webpack) for how to include additional custom Sass and optimize your build by importing only the parts of Bootstrap's CSS and JS that you need.
 

site/layouts/_default/_markup/render-image.html

@@ -0,0 +1,8 @@
+{{- $originalSrc := .Destination | safeURL -}}
+{{- $localImgPath := path.Join "/site/static/docs" site.Params.docs_version $originalSrc -}}
+{{- /* This shouldn't be needed but we have a weird folder structure with version included... */ -}}
+{{- $src := urls.JoinPath "/docs" site.Params.docs_version $originalSrc -}}
+{{- $config := imageConfig $localImgPath -}}
+{{- $classes := "d-block img-fluid" -}}
+
+<img src="{{ $src }}" class="{{ $classes }}" alt="{{ .Text }}" width="{{ $config.Width }}" height="{{ $config.Height }}" loading="lazy">